Term
| Location(s) of fructokinase? |
|
Definition
|
|
Term
|
Definition
| Traps fructose as fructose-1-phosphate (DIFFERENT from glycolytic intermediate fructose-6-phosphate) |
|
|
Term
| Describe the reaction catalyzed by Aldolase B. |
|
Definition
| Fructose-1-phosphate <-> glyceraldehyde and dihydroxyacetone phosphate |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Isozymes (also known as isoenzymes or more generally as Multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. |
|
|
Term
| Aldolase B is located where? |
|
Definition
| Found in liver, kidney, and intestine (same as fructokinase) |
|
|
Term
| Which product of Aldolase B is not phosphorylated? |
|
Definition
|
|
Term
| Glyceraldehyde the non phosphorylated product of Aldolase B is phosphorylated by? |
|
Definition
| It is phosphorylated by coupling of ATP -> ADP by Triokinase to form glyceraldehyde-3-phosphate (G3P). |
|
|
Term
| Which major regulatory step in glycolysis is bypassed by aldolase B? |
|
Definition
Fructose-6-phosphate to fructose-1,6-bisphosphate by PFK.
(Because Aldolase B turns F-1-P into Dihydroxyacetone phosphate (& and Glyceraldehyde), the Dihydroxyacetone phosphate is then converted into F-1,6-BP by aldolase (bypassing F-6-P to F-1,6-BP by PFK in the glucose pathway) |
|
|
Term
|
Definition
|
|
Term
| Fructose metabolism is unregulated because it ______ |
|
Definition
|
|
Term
| Explain how excess fructose can lead to excess lactate production. |
|
Definition
| Fructose metabolism creates pyruvate faster (more glycolytic intermediates coming in via triose phosphates, and F-1-P stimulates pyruvate kinase) and leads to excess pyruvate production. If TCA gets saturated, lactate can build up. Fructose metabolism is unregulated (bypasses PFK step). |
|
|
Term
| How can excess fructose can elevate the blood sugar of an untreated type 1 diabetic. |
|
Definition
| The activity of fructokinase exceeds that of aldolase B, and F-1-P accumulates, directing glucose into glycogen synthesis. Fructose is metabolized faster than glucose and goes through the pathway unregulated. |
|
|
Term
| Name the defective enzyme in essential fructosuria. |
|
Definition
|
|
Term
| Is Essential Fructosuria a dangerous condition? |
|
Definition
| No, it’s benign. No clinical presentation except elevated blood and urine fructose. |
|
|
Term
| How would you detect Essential Fructosuria if you had lab data on the reducing sugar concentration of the urine along with an enzymatic test for glucose? |
|
Definition
| Elevated blood and urine glucose. Reducing sugar should be positive; glucose oxidase should be negative in the blood. |
|
|
Term
| Name the defective enzyme in Hereditary Fructose Intolerance |
|
Definition
|
|
Term
| What is the pathology associated with Hereditary Fructose Intolerance? |
|
Definition
| Nausea, cirrhosis, and hypoglycemia. (treat by limiting fructose) |
|
|
Term
| What metabolite accumulates in Hereditary Fructose Intolerance? |
|
Definition
| Fructose-1-phosphate (because Aldolase B is deffective). Hepatotoxic |
|
|
Term
| Describe the conversion of galactose to UDP-glucose in the cell. |
|
Definition
1. Galactose -> Galactose-1-P by Galactokinase coupling with ATP->ADP.
2. Galactose-1-P -> UDP-Galactose by "Galactose-1-P Uridyl Transferase" by the coupling of UDP-Glucose to Glucose-1-P
3. UDP-Galactose -> UDP-Glucose by UDP-Galactose 4-Epimerase
4. Reaction 2, the coupling to form G-1-P |
|
|
Term
| What are the products of the galactokinase reaction? |
|
Definition
| Galactose to Galactose-1-P by Galactokinase by the coupling of ATP->ADP |
|
|
Term
| What are the substrates for the galactose 1-phosphate uridyl transferase reaction? |
|
Definition
Galactose-1-phosphate is converted to UDP-galactose.
UDP-glucose also goes to glucose-1-phosphate. |
|
|
Term
| UDP-galactose interconverted into _____ by _____ enzyme. |
|
Definition
| UDP-glucose, catalyzed by UDP-galactose 4-epimerase. |
|
|
Term
|
Definition
| Epimers are monosaccharides differing in the orientation of substituents around one of their asymmetrical carbons. |
|
|
Term
| Classical Galactosemia results from a deficiency in ____ |
|
Definition
| transferase enzyme (Galactose-1P uridyl transferase) |
|
|
Term
| Classical Galactosemia results in a toxic buildup of _____. |
|
Definition
|
|
Term
| Symptoms of Classical Galactosemia? |
|
Definition
| Nausea, avoidance of feeding, mental retardation, cataracts |
|
|
Term
| Cataracts associated with Classical Galactosemia is a result of? |
|
Definition
| due to elevated galactitol in lens |
|
|
Term
| With Classical Galactosemia, Galactitol is produced by ______. |
|
Definition
aldose reductase
(reduced aldehyde group into an alcohol polyol pathway) |
|
|
Term
| Two types of galactosemia: _____ |
|
Definition
Galactokinase deficiency (Minor)
Classical Galactosemia |
|
|
Term
| Galactokinase deficiency results in _____ |
|
Definition
|
|
Term
| Galactokinase deficiency can result in ______ in advanced stages. |
|
Definition
|
|
Term
| What enzyme is defective in classical galactosemia? |
|
Definition
| Galactose-1P uridyl transferase |
|
|
Term
| What enzyme is defective in the minor form of galactosemia? |
|
Definition
|
|
Term
| What symptom is produced in both types of galactosemia and what is the agent that causes the disease? |
|
Definition
| Cataracts. Caused by galactitol formed by aldose reductase |
|
|
Term
| What is the offending metabolite in classical galactosemia that leads to liver dysfunction and mental deficiency? |
|
Definition
|
|
Term
| Describe the steps in the polyol pathway for the synthesis of fructose from glucose. |
|
Definition
1. Glucose -> Sorbitol by Aldose Reductase coupled with the oxidation of NADPH->NAD+
2. Sorbitol -> Fructorse by Sorbitol DH coupled with the reduction of NAD+ -> NADH
3. NADPH is also oxidized by Aldose Reductase in conversion of Galactose to Galactitol (Toxis product that causes cataracts in galactosemia) |
|
|
Term
| Where does the polyol pathway occur in the body? |
|
Definition
| Seminal vesicle, eyes (retina, lens), peripheral nerves, blood vessels |
|
|
Term
| What cofactors are required for the polyol pathway? |
|
Definition
| NADPH -> NADP+ and NAD+ -> NADH |
|
|
Term
| Explain the formation of cataracts in patients with uncontrolled diabetes. |
|
Definition
| Excess blood glucose leads to buildup of sorbitol. Accumulation in the lens can lead to cataracts (lens proteins precipitate out.) |
|
|
Term
| Which polypol causes cataracts in diabetics? |
|
Definition
|
|
Term
| Which polypol causes cataracts in galactosemia? |
|
Definition
|
|
Term
| Explain the formation of cataracts in patients with uncontrolled diabetes. |
|
Definition
| Excess blood glucose leads to buildup of sorbitol. Accumulation in the lens can lead to cataracts (lens proteins precipitate out.) |
|
|
Term
| Which polypol causes cataracts in diabetics? |
|
Definition
|
|
Term
| Which polypol causes cataracts in galactosemia? |
|
Definition
|
|
Term
| Oxidative branch of the pentose phosphate pathway provides a continual source of _____ |
|
Definition
| NADPH and ribulose-5-phosphate |
|
|
Term
| Regulated step of the Oxidative branch of the pentose phosphate pathway? |
|
Definition
1st
Glucose-6-P -> 6-Phosphoglucono-Delta-Lactone by Glucose-6-P DH which is coupled to the reduction of NADP+ to NADPH
Regulated by NADP+, produces NADPH |
|
|
Term
| Start product and End Product of the Oxidative Branch of the Pentose Phosphate Pathway? |
|
Definition
G-6-P
Ribulose-5-Phosphate |
|
|
Term
| For the Oxidative Branch of the Pentose Phosphate Pathway, how many NADPH are produced per glucose? |
|
Definition
|
|
Term
| What is the end metabolite of the oxidative pathway of PPP? |
|
Definition
|
|
Term
| How is glucose 6-phosphate dehydrogenase of the Oxidative Branch of the PPP regulated? |
|
Definition
Regulated by NADP+ concentration. Cells contain more NADPH than NADP+. When NADP+ increases, G6PD is activated to make more NADPH. When there is a lot (enough) NADPH or not enough NADP+, then G6PD is inactivated.
NADP+/NADPH = 1/70, so NADP+ is limiting. |
|
|
Term
| The non-oxidative branch of the pentose phosphate pathway links ribulose-5-phosphate to ____ and _____ pathways |
|
Definition
|
|
Term
| What vitamin does transketolase of the non-oxidative branch of the PPP use as a cofactor? |
|
Definition
|
|
Term
| Which enzyme of the non-oxidative branch of the PPP catalyzes the formation of ribose 5-phosphate? What is the substrate? |
|
Definition
Pentose phosphate isomerase:
ribulose-5-phosphate -> ribose-5-phosphate
ribulose-5-phosphate |
|
|
Term
| Which tissues have the greatest pentose phosphate pathway activity? |
|
Definition
Tissues with active fatty acid or cholesterol synthesis:
- Liver
- Adipose tissue
- Adrenal cortex
- Lactating mammary gland
- Cells exposed to high oxygen partial pressure (ex: Cornea of eye)
- MINIMAL in brain or muscle |
|
|
Term
| Describe how the pentose phosphate pathway can produce ribose only. |
|
Definition
| Use non-oxidative branch only. Have to come down thru glycolysis, make G3P and F6P, go through nonoxidative branch and make ribose. |
|
|
Term
| Describe how the pentose phosphate pathway can produce NADPH only. |
|
Definition
| Oxidative branch plus nonoxidative branch. 5C is recycled thru glycolysis. G3P and F6P are made from nonoxidative branch, and they are recycled to glucose-6-phosphate in gluconeogenic reactions. Theoretically, whole glucose molecule oxidized to CO2 and NADPH. |
|
|
Term
| Describe how the pentose phosphate pathway can produce NADPH and ribose. |
|
Definition
|
|
Term
| Describe the reduction of glutathione by glutathione reductase. |
|
Definition
| The reduced form of glutathione(GSH) acts as a reducing agent for peroxides. Only the reduced form of glutathione is an antioxidant (neutralizes free radicals). Glutathione reductase takes glutathione from oxidized state GSSG with a disulfide bond, back to GSH so it can neutralize more free radicals. |
|
|
Term
| With G6P DH deficiency, less _____ is made in the pentose phosphate pathway. |
|
Definition
|
|
Term
| Glutathione reductase needs ____, so people with G6P DH deficiency don’t have as good _____ defense. |
|
Definition
|
|
Term
| Glucose 6-phosphate dehydrogenase deficiency leaves one vulnerable to ______. |
|
Definition
|
|
Term
| ____ can come from fava beans |
|
Definition
|
|
Term
| Glucose 6-phosphate dehydrogenase deficiency is typically ______, until administered _____ drugs. |
|
Definition
asymptomatic
peroxide producing |
|
|
Term
| With peroxide-producing drugs, more of the enzyme ______ is needed to turn GSSG -> GSH, which requires _____ as a cofactor. |
|
Definition
|
|
Term
| Following adminstration of peroxide producing drugs in a Glucose 6-phosphate dehydrogenase deficienct individual, Membrane proteins become ______,aggregates of _____ become visible in cell, and ____ crisis in 2-3 days. |
|
Definition
covalently cross-linked
oxidized hemoglobin
hemolytic |
|
|
Term
|
Definition
|
|
Term
| What is glutathione's role in the cell? |
|
Definition
| Reduces free radicals through GSH peroxidase |
|
|
Term
| Describe the basic structure of a fatty acid. |
|
Definition
| R-COOH. Unbranched hydrocarbon chain with carboxyl at one end. |
|
|
Term
| Do fatty acids carry a charge at physiologic pH? |
|
Definition
| pK is close to 4.8. So yes |
|
|
Term
| Are fatty acids branched? |
|
Definition
|
|
Term
| What is a saturated fatty acid saturated with? |
|
Definition
| Hydrogens. Single bonds only! |
|
|
Term
| Are fatty acids with an odd number of carbons found in humans? |
|
Definition
| Yes but most are even-numbered because acetyl-CoA is C2 |
|
|
Term
| What does amphipathic mean? |
|
Definition
| Amphipathic: containing hydrophilic and hydrophobic portions in the same molecule. |
|
|
Term
| _____ are formed by single-chain fatty acids because the ____ ends aggregate in the middle and the _____ stay on the outside. |
|
Definition
Micelles
hydrophobic
polar (hydrophilic heads) |
|
|
Term
| Describe the major classes of fatty acids by length. |
|
Definition
| Short: 2-4 C Medium: 6-12 C Long: 14-26 C (most of the fats we eat are of this type) |
|
|
Term
| Give the number of carbons in butyric, lauric, palmitic, and stearic acid. |
|
Definition
Butyric: 4 (short)
Lauric: 12 (long)
Palmitic: 15 (long)
Stearic: 18 (long) |
|
|
Term
| Give the unsaturated counterparts for palmitic acid. |
|
Definition
| Palmitic -> Palmitoleic (16:1;9) |
|
|
Term
| Give the unsaturated counterparts for stearic acid. |
|
Definition
| Stearic -> Oleic (18:1;9) Linoleic (18:2;9,12) alpha-linolenic (18:3;9;12;15) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Name a fatty acid that is 20 carbons in length with four double bonds. |
|
Definition
|
|
Term
| Is there free rotation around the double bond of cis or trans? |
|
Definition
|
|
Term
| ______ configuration favors extended hydrocarbon chain. |
|
Definition
|
|
Term
| Cis forms angle of ______. |
|
Definition
|
|
Term
| Which is common in nature,cis or trans configurations of fatty acids? |
|
Definition
|
|
Term
| Bent shape of ____ configuration in fatty acids allows fluid motion of membranes |
|
Definition
|
|
Term
| List the factors that decrease melting temperature of fatty acids. |
|
Definition
- Double bonds decrease the melting temperature
- Fewer carbons in the carbon chain |
|
|
Term
| Unsaturated fatty acid is USUALLY on carbon ___ of a triglyceride. |
|
Definition
|
|
Term
| Saturated fatty acid is USUALLY on carbon ___ of a triglyceride. |
|
Definition
|
|
Term
| Bond formed between the fatty acid and glycerol? |
|
Definition
| ester (Glycerol Esterification) |
|
|
Term
| Binding of epinephrine to its receptor increases ______. |
|
Definition
|
|
Term
| Binding of epinephrine to its receptor increases cAMP levels, which then increases ______. |
|
Definition
| PKA levels (Protein kinase levels) |
|
|
Term
| Describe the action of epinephrine in mobilizing fatty acids. |
|
Definition
1) Receptor binding increases cAMP
2) cAMP increases PKA (protein kinase A)
3) PKA phosphorylates enzymes. |
|
|
Term
| Where does epinephrine mobilize fatty acids? |
|
Definition
| In muscle and adipose tissue |
|
|
Term
| In epinephrine mobilizing fatty acids it leads to the activation of _______ in adipose tissue, which is the only regulated step in fat oxidation. |
|
Definition
|
|
Term
| Fat-associated perilipin and hormone-sensitive lipase are _____ during mobilization. |
|
Definition
|
|
Term
| Non-phosphorylated perilipin does what? |
|
Definition
| protects fat from degradation. |
|
|
Term
| Fat mobilization is needed during fasting to provide energy for _____ in liver. |
|
Definition
|
|
Term
| Fat mobilization needed during _____. |
|
Definition
|
|
Term
| Epinephrine (and norepinephrine) work in _______. |
|
Definition
| muscle and adipose tissue |
|
|
Term
| With Fat Mobilization, insulin works in ______ |
|
Definition
| Insulin works in all three: liver, muscle and adipose tissue. |
|
|
Term
| With Fat Mobilization, insulin works in liver, muscle and adipose tissue by leading to the _____ of hormone-sensitive lipase and ______ of protein phosphatase activity |
|
Definition
inactivation
stimulation of |
|
|
Term
| Epinephrine (and norepinephrine) lead to the ______ of hormone-sensitive lipase in adipose |
|
Definition
|
|
Term
| How do short and medium chain fatty acids get into the mitochondria? |
|
Definition
| Short and medium chain fatty acids can just diffuse passively through the membrane to get in |
|
|
Term
| How do Long chain fatty acids get into the mitochondria? |
|
Definition
| long chain fatty acids need the carnitine shuttle to enter MT. |
|
|
Term
| _______ join and release long chain FFA to and from Carnitine |
|
Definition
| Carnitine-palmitoyl transferase (I and II) |
|
|
Term
| Carnitine-palmitoyl transferase (I and II) are inhibited by ______ |
|
Definition
| malonyl-CoA (cytoplasmic precursor for FFA synthesis) |
|
|
Term
| malonyl-CoA is a cytoplasmic precursor for ______ |
|
Definition
|
|
Term
| Where does beta-oxidation occur? |
|
Definition
|
|
Term
| FFA are metabolically activated to ______. |
|
Definition
|
|
Term
| _____ FFA chains are activated in the mitochondrion. |
|
Definition
|
|
Term
| _____ chain fatty acids are activated in the cytoplasm by enzymes on ER membrane and outer mitochondrial membrane. |
|
Definition
|
|
Term
| Can acyl-CoA molecules diffuse into the mitochondrion? |
|
Definition
|
|
Term
| How do acyl-CoA molecules get into the mitochondrion? |
|
Definition
| Short and medium chains can diffuse and be activated in the mitochondrion. Long chains (> 12 C) are activated in the cytoplasm and transported via carnitine shuttle |
|
|
Term
| How many forms of carnitine palmitoyl transferase are there? |
|
Definition
|
|
Term
| What is the product of the cytoplasmic form of carnitine palmitoyl transferase (I)? |
|
Definition
-CoA-SH
-Acyl-carnitine (which is then shuttled across IMM) |
|
|
Term
| What is the product of the MT form of carnitine palmitoyl transferase (II)? |
|
Definition
|
|
Term
| Long chain FFA activated in? |
|
Definition
|
|
Term
| Short-Medium Chain FFA activated in? |
|
Definition
|
|
Term
| Beta-oxidation is regulated mainly at level of _____ because it depends on plasma free fatty acid level. |
|
Definition
| hormone-sensitive adipose tissue lipase |
|
|
Term
| Each cycle of beta oxidation produces: |
|
Definition
- 1 acetyl-CoA
- 1 FADH2
- 1 NADH
- 1 n-2 acyl-CoA |
|
|
Term
| Does the oxidation occur at the omega end of the molecule or the alpha end? |
|
Definition
alpha
It’s called beta oxidation because it oxidizes the beta carbon (3rd) |
|
|
Term
| Acyl-CoA dehydrogenase cofactor? |
|
Definition
|
|
Term
| 3-L-hydroxyacyl-CoA dehydrogenase cofactor? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| B-ketothiolase catalyzes what reaction? |
|
Definition
The final one of Beta Oxidation, the addition of a CoA group to the Beta Carbon.
Produces Acyl-CoA and Acetyl-CoA |
|
|
Term
| What happens to the products of the reaction catalyzed by B-ketothiolase (final step of beta oxidation) |
|
Definition
Acetyl-CoA ->TCA Cycle
Acyl-CoA -> Recycled until the end of the beta oxidation cycle when the final C4 produces two Acetyl-CoA |
|
|
Term
|
Definition
|
|
Term
| How is the β-oxidation pathway is regulated? |
|
Definition
| Regulated by SUPPLY OF FATTY ACIDS only. |
|
|
Term
| If fatty acids get out of the fat cell they will be _____ and can pile up in the liver by ______ and lead to _____ |
|
Definition
oxidized
esterification
fatty liver |
|
|
Term
| Carnitine-palmitoyl transferase is allosterically inhibited by ____, which is made in _____. |
|
Definition
malonyl-CoA
fatty acid synthesis |
|
|
Term
| Fatty acid oxidation is inhibited when ______ is active. |
|
Definition
|
|
Term
| List the different forms of acyl-CoA dehydrogenase (1st step of Beta Oxidation) and give their substrate specificity. |
|
Definition
| 3 forms for long, medium, and short chain fatty acids. |
|
|
Term
| Carnitine deficiency produces what symptoms? |
|
Definition
fasting nonketotic hypoglycemia (Fat burning provides only source of energy for gluconeogenesis, so can’t make glucose in fasting state)
&
heart arrhythmias (heart, next to brain, highest consumer of CO2. Loves burning fat) |
|
|
Term
| With a Carnitine deficiency FFA would still go to the liver, but but wouldn’t be able to get into cell ____, which leads to _____. |
|
Definition
|
|
Term
| Carnitine deficiency treat by eating _____ |
|
Definition
|
|
Term
| With a (Medium) Acyl-CoA dehydrogenase deficiency, FFA are oxidized until _____ |
|
Definition
| FFA oxidized until 10-12 carbons |
|
|
Term
| (Medium) Acyl-CoA dehydrogenase deficiency produces what symptoms? |
|
Definition
| Fasting nonketotic hypoglycemia (Fat burning provides only source of energy for gluconeogenesis, so can’t make glucose in fasting state). |
|
|
Term
| (Medium) Acyl-CoA dehydrogenase deficiency is dangerous only in ______ |
|
Definition
| only extreme or frequent fasting. |
|
|
Term
| Unsaturated fatty acids enter the beta-oxidation pathway through ____ to resemble _____ via _____ enzyme. |
|
Definition
Double bond modified to resemble the trans-enoyl intermediate via enoyl-CoA isomerase.
This is the second intermediate in B oxidation |
|
|
Term
| Unsaturated FFAs enter ____ β-oxidation after modification to trans configuration by isomerase enzyme |
|
Definition
|
|
Term
| With Odd-chain Fatty Acid Oxidation, Normal β-oxidation proceeds until _____ |
|
Definition
| propionate is formed (Propionyl-CoA) |
|
|
Term
| With Odd-chain Fatty Acid Oxidation, Propionyl-CoA converted to ______, which is then ______ |
|
Definition
succinyl-CoA
fed into the TCA which is also in the MT Matrix |
|
|
Term
| List the CoA intermediates involved in odd-chain FFA oxidation. |
|
Definition
Propionyl CoA -> D-methylmalonyl-CoA via methylmalonyl-CoA racemase (requires Biotin)
L-methylmalonyl-CoA -> succinyl CoA involves methylmalonyl-CoA mutase (B12) |
|
|
Term
| What is the last CoA derivative produced by beta-oxidation of odd numbered FFA’s? |
|
Definition
| Propionyl-CoA (eventually converted to succinyl-CoA) |
|
|
Term
| How is Propionyl-CoA converted methylmalonyl-CoA? |
|
Definition
| Propionyl-CoA carboxylase |
|
|
Term
| Propionyl-CoA carboxylase requires what cofactors? |
|
Definition
|
|
Term
| Does the conversion of Propionyl-CoA to methylmalonyl-CoA by Propionyl-CoA carboxylase require energy? |
|
Definition
|
|
Term
| Methylmalonyl CoA mutase, along with _____ cofactor, converts L-methylmalonyl-CoA to ______. |
|
Definition
|
|
Term
| α-oxidation, Oxidizes ______ and releases ______, shortening fatty acid by ___carbon at a time. |
|
Definition
C2 (α-carbon)
C1 as CO2
ONE |
|
|
Term
| α-oxidation used for ____ FFA. |
|
Definition
|
|
Term
| Refsum disease is an inherited defect of ______ that causes a accumulation of _____. |
|
Definition
peroxisomal α-oxidation
phytanic acid. |
|
|
Term
| α-oxidation is needed for the oxidation of _______. |
|
Definition
| methylated fatty acid (ex: phytanic acid) |
|
|
Term
| Methylated ____ carbon cannot be ___-oxidized |
|
Definition
|
|
Term
| ____ is needed to shorten phytanic acid by one C, followed by β-oxidation that yields ______ rather than acetyl-CoA |
|
Definition
α-oxidation
propionyl-CoA |
|
|
Term
| Refsum disease Leads to abnormal ______ symptoms |
|
Definition
|
|
Term
| Peroxisomes required for beta oxidation of _________. |
|
Definition
| very long chain FFA (20-26C) |
|
|
Term
| With Peroxisomal β-oxidation no ____ produced but shortened enough for ______. |
|
Definition
NADH
mitochondria to metabolize |
|
|
Term
| No ____ is produced in peroxisomal Beta oxidation. |
|
Definition
|
|
Term
| _____ is produced in Peroxisomal β-oxidation and then degraded by ______. |
|
Definition
|
|
Term
| Formation of ketone bodies only occurs where? |
|
Definition
|
|
Term
| If fat is metabolized quickly, _____ will accumulate and will be shunted towards ketone body formation. |
|
Definition
|
|
Term
| What are the precursors for the synthesis of 3-hydroxy-3-methylglutaryl CoA (aka,HMG CoA)? {Ketone Body Formation} |
|
Definition
2 acetyl CoA <-> acetoacetylCoA via Beta-Ketothiolase
acetoacetylCoA <-> HMG CoA via HMG-CoA Synthase
Also fatty acids can make acetoacetyl-CoA via B-oxidation
24.2 What |
|
|
Term
| What are the two different fates of HMG CoA in ketone body formation? |
|
Definition
| Acetoacetate and acetyl-CoA |
|
|
Term
| HMG CoA -> Acetoacetate and acetyl-CoA by the enzyme _______. |
|
Definition
|
|
Term
| What steroid is made from HMG CoA? |
|
Definition
|
|
Term
| What is the fate and function of acetone formed in the liver? |
|
Definition
| No biological function. Exhaled through the lungs. |
|
|
Term
| How is acetone formed in the liver? |
|
Definition
| One of two pathways for Acetoacetate, in which it undergoes spontanteous decarboxylation |
|
|
Term
| How is acetoacetate formed in the liver? |
|
Definition
| Acetoacetate is formed in addition to Acetyl-CoA from HMG-CoA by HMG-CoA Lyase {Ketone Body Formation} |
|
|
Term
| What is the fate of acetoacetate formed in the liver? |
|
Definition
| sent from liver to other tissues for oxidation. Makes energy. |
|
|
Term
| What is the fate of 3-hydroxybutyrate formed in the liver? |
|
Definition
| sent from liver to other tissues for oxidation. Makes energy. Reversible reaction to acetoacetate (via B-hydroxybutyrate dehydrogenase) makes NADH |
|
|
Term
| How is 3-hydroxybutyrate formed in the liver? |
|
Definition
| It is formed from Acetoacetate via beta-hydroxybutyrate DH {Ketone body formation} |
|
|
Term
| ______ used to make acetyl-CoA from acetoacetyl-CoA. |
|
Definition
|
|
Term
| Ketone bodies are only used by the brain when? |
|
Definition
| Used by brain only in starvation |
|
|
Term
| What limits the entry of acetyl CoA into the citric acid cycle eventually leading to its conversion into ketone bodies? |
|
Definition
| - When the body has no free carbohydrates available, fat must be broken down into acetyl-CoA in order to get energy. Acetyl-CoA is not being recycled through the citric acid cycle because the citric acid cycle intermediates (mainly oxaloacetate) have been depleted to feed the gluconeogenesis pathway, and the resulting accumulation of acetyl-CoA activates ketogenesis. |
|
|
Term
| What physiological conditions will lead to the limiting conditions that lead to ketone body formation? |
|
Definition
| Accumulation of Acetyl CoA, because not being fed into TCA, because all intermediates have been consumed in gluconegoensis, thus Starvation or low-carb diet will lead to this limiting conidition. |
|
|
Term
| 3-hydroxybutyrate to acetoacetate results via _____ results in the formation of ______. |
|
Definition
|
|
Term
| _____ is needed for acetoacetate to acetyl-CoA, because _____ |
|
Definition
Succinyl-CoA
CoA comes from succinyl-CoA |
|
|
Term
| How is acetoacetate activated in the peripheral tissues? |
|
Definition
Beta-Hydroxybutyrate is converted back into acetoacetate resulting in the formation of NADH.
Acetoacetate is then reacted with Succinyl-CoA, forming Acetoacetyl-CoA + Succinate (Liver lacks the enzyme for this reaction)
Acetoacetyl-CoA is combined with CoA-SH breaking it into 2 Acetyl-CoA by B-Ketothiolase (Beta Oxidation Enzyme) |
|
|
Term
| Do ketones form in a carnitine deficiency? |
|
Definition
|
|
Term
| Ketogenesis occurs when ___ is metabolized too quickly and ____ piles up. |
|
Definition
|
|
Term
| In carnitine deficiency, long-chain fatty acids can’t get into the mitochondria as quickly for ____. |
|
Definition
|
|
Term
| Acyl-CoA that cannot be transported into mitochondrion is diverted into ______ synthesis leading to _____ condition. |
|
Definition
triglyceride
fatty liver/ muscle |
|
|
Term
| Carnitine deficiency in the liver leads to ______ during periods of extended fasting. |
|
Definition
|
|
Term
| During fasting, beta-oxidation is needed to produce ____ for ketogenesis and ___ for gluconeogenesis, therefore both pathways are compromised in _____ deficiency. |
|
Definition
|
|
Term
| carnitine deficiency causes ____ & ____ upon exertion. |
|
Definition
| weakness and muscle cramps |
|
|
Term
| HMG-CoA Synthase does what? |
|
Definition
| Turns acetoacetyl-CoA into HMG-CoA {Ketone Body Formation} |
|
|
Term
|
Definition
| cleaves HMG-CoA into Acetyl-CoA and Acetoacetate {Ketone Body Formation} |
|
|
Term
| HMG-CoA Reductase does what? |
|
Definition
| involved in cholesterol synthesis; reduces HMG-CoA to mevanolate |
|
|
Term
| Ketone bodies are used as a _____ energy source. |
|
Definition
|
|
Term
| During fasting, large amount of _____ are released. |
|
Definition
|
|
Term
| Acetyl-CoA formed by β-oxidation is not readily used for _____ during fasting |
|
Definition
|
|
Term
| Oxidation of Acetyl-CoA by TCA cycle is minimal because NADH and FADH2 formed during _____ provide enough fuel for respiratory chain |
|
Definition
|
|
Term
| What is the rate limiting enzyme of Ketogenesis? |
|
Definition
|
|
Term
| HMG-CoA synthase the rate limiting enzyme of Ketogenesis is stimulated by: ______ |
|
Definition
| fasting, dietary fat, fatty acids, and insulin deficiency. |
|
|
Term
| Two ways that ethanol metabolism can contribute to acidosis are? |
|
Definition
| Through Ketone bodies and Lactic Acid |
|
|
Term
| How does ethanol metabolism contribute to acidosis through lactic acid? |
|
Definition
| Ethanol metabolism leads to large amounts of NADH being produced which causes pyruvate to build up and then converted to lactate |
|
|
Term
| How does ethanol metabolism contribute to acidosis through ketone bodies? |
|
Definition
| Ethanol -> Acetaldehyde -> Acetate -> Acetyl CoA -> Ketone bodies |
|
|
Term
| How can ethanol metabolism can produce hypoglycemia? |
|
Definition
Impairs gluconeogenesis
- Decrease in amount of pyruvate due to increased NADH
- Depletion of OAA |
|
|
Term
| Ethanol Metabolism leads to a _____NADH/NAD+ ratio |
|
Definition
|
|
Term
| Ethanol Metabolism leads to a higher NADH/NAD+ ratio, which increases the rate of conversion of DHAP-> ______ |
|
Definition
|
|
Term
| Ethanol metabolism leads to _____ synthesis of triacylglycerol |
|
Definition
|
|
Term
| Ethanol metabolism leads to ______ VLDL levels |
|
Definition
|
|
Term
| What is the site of action for pancreatic lipase? |
|
Definition
| Pancreatic lipase: Intestinal lumen (breaks down triglycerides for absorption) |
|
|
Term
| Site of action of hormone-sensitive lipase |
|
Definition
| adipose tissue – inside the cells |
|
|
Term
| Hormone-sensitive lipase function? |
|
Definition
| Works in adipose tissue – inside the cells (degrades fat droplet and hydrolyze triglycerides -> creates free fatty acids |
|
|
Term
| Site of action for Hepatic lipase? |
|
Definition
| Outside liver cells, in contact with blood or extracellular fluid |
|
|
Term
| Hepatic lipase converts ____ to ____ by hydrolyzing excess triglyceride and phospholipid |
|
Definition
|
|
Term
| Site of action for Lipoprotein lipase is located where? |
|
Definition
| capillary, on surface of endothelial cell in muscle, heart, and adipose tissue. |
|
|
Term
| Lipoprotein lipase releases FFA from _____ or _____ for uptake by adipose tissue. |
|
Definition
|
|
Term
| Lipoprotein lipase requires _____ cofactor |
|
Definition
|
|
Term
| In the intestinal lumen Triglyceride in the gut is broken down into __________. |
|
Definition
| 2-monoacylglycerol and 2 free fatty acids. |
|
|
Term
| Triglyceride in the gut is broken down into 2-monoacylglycerol and 2 free fatty acids. These components enter the ______ |
|
Definition
|
|
Term
| The two fatty acids that are adsorbed by the mucosal cell into the ER from the intestinal lumen is then converted into ______ by ______ enzyme that uses _____ in order to ______. |
|
Definition
converted into 2 acyl-CoA
Acyl-CoA synthetase
ATP to AMP
activate them in order to keep them within the cell |
|
|
Term
| The Acyl-CoAs formed by the activation of the FFA in the Mucosal Cell ER then react with _______ to reform ________. |
|
Definition
2-monoacylglycerol
triglyceride |
|
|
Term
| The triglycerides reformed in the Mucosal ER is then assembled into _______. |
|
Definition
| Fat Droplets called Chylomicrons |
|
|
Term
| Fat Droplets called Chylomicrons assembled in the Mucosal ER are then transported through the _____ and into the ______. |
|
Definition
|
|
Term
|
Definition
| The endothelium is the thin layer of cells that lines the interior surface of blood vessels and lymphatic vessels |
|
|
Term
| On the endothelial cells of the capillaries there are _______ lipases. |
|
Definition
| lipoprotein lipases (LPLs) |
|
|
Term
| On the endothelial cells of the capillaries there are lipoprotein lipases (LPLs) that bind to the chylomicrons and hydrolyze the triglycerides into ______ for cell uptake. |
|
Definition
| back to free fatty acids and 2-monoacylglyceral |
|
|
Term
| Feeding raises LPL (lipoprotein lipases) in ____, but reduces it in _____. |
|
Definition
|
|
Term
| Which two forms of fatty acid are absorbed from the gut? |
|
Definition
| 2 free fatty acids and 1 molecule of 2-monoacylglycerol (fatty acid still on C2). |
|
|
Term
| What enzyme is involved in fatty acid activation? |
|
Definition
| Acyl-CoA synthetase (uses ATP). |
|
|
Term
| Why is it necessary for Acyl-CoA synthetase to activate FFA in the Mucosal ER? |
|
Definition
| Traps fatty acid in the cell |
|
|
Term
| Is phosphatidic acid involved in triglyceride synthesis in the intestinal mucosa? |
|
Definition
|
|
Term
|
Definition
| hosphatidic acids are the simplest diacyl-glycerophospholipids.[1] |
|
|
Term
| What is the source of glycerol for triglyceride esterification in the mucosa? |
|
Definition
|
|
Term
| Are the triglycerides that are assembled in the mucosa picked up by the hepatic portal like all the other products of digestion? |
|
Definition
|
|
Term
| How do the triglycerides that are assembled in the mucosa get into the general circulation? |
|
Definition
| They go through the lymph first, and are carried to the left brachiocephalic vein by the thoracic duct. |
|
|
Term
| Long chain TG packaged in _____ and transported _______. |
|
Definition
chylomicrons
by lymph system to the blood |
|
|
Term
| Short and medium chain TG FFA transported ________, attached to ______. |
|
Definition
directly thru portal to liver
albumin |
|
|
Term
| _____ TG circulate to tissues |
|
Definition
|
|
Term
| Which is less hydrophobic Short and Medium chain TG or Long chain TG |
|
Definition
| Short and Medium Chain TG |
|
|
Term
| How are free fatty acids are transported in blood |
|
Definition
|
|
Term
| Glycerol-3-phosphate dehydrogenase converts _____ to glycerol-3-phosphate |
|
Definition
|
|
Term
| DHAP is a _____ intermediate. |
|
Definition
|
|
Term
| Insulin triggers fat storage during _____ state and breakdown during ______. |
|
Definition
|
|
Term
| Insulin inhibits ______ lipase in adipose tissue |
|
Definition
hormone sensitive lipase
(so it remains unphosphorylated and can’t digest the fat droplet) |
|
|
Term
| insulin _____ the mobilization of fat from triglycerides. |
|
Definition
|
|
Term
| Insulin _____ LPL in capillaries of adipose tissue. |
|
Definition
stimulates
induction of glycerol phosphate-acyl transferase (adds first fatty acid to glycerol phosphate in biosynthetic pathway) |
|
|
Term
| Insulin stimulates glycolytic pathway, so more ____ is made that can be made into ______ and into triglycerides. |
|
Definition
DHAP
glycerol-3-phosphate |
|
|
Term
| What key fat synthesis enzymes are stimulated by insulin? |
|
Definition
Acetyl-CoA carboxylase (makes malonyl-CoA from acetyl-CoA)
PP2A (protein phosphatase 2A), which dephosphorylates acetyl-CoA carboxylase to activate it |
|
|
Term
| Which form of Acetyl-CoA carboxylase is active? |
|
Definition
|
|
Term
| What dephosphorylates Acetyl-CoA carboxylase? |
|
Definition
| PP2A (protein phosphatase 2A) |
|
|
Term
| Name a key fat mobilizing enzyme that is inhibited by insulin? |
|
Definition
| Hormone-sensitive lipase (mediated by activation of cAMP-degrading phosphodiesterase). |
|
|
Term
| Hormone-sensitive lipase is inhibited by _____ |
|
Definition
|
|
Term
| Hormone-sensitive lipase works in the adipose cells by _______ |
|
Definition
| cleaving TG into FFA for transport in the blood by albumin |
|
|
Term
| What is the first committed step of FA synthesis. |
|
Definition
| converting acetyl CoA to malonyl CoA by Acetyl-CoA carboxylase |
|
|
Term
| Acetyl-CoA carboxylase reaction... |
|
Definition
Converts Acetyl-CoA into Malonyl CoA by the use of CO2 and the hydrolysis of ATP to ADP
it is the first committed step of fat synthesis |
|
|
Term
| How is Acetyl-CoA carboxylase similar to pyruvate carboxylase? |
|
Definition
|
|
Term
| What is the rate limiting step in the synthesis of fatty acids? |
|
Definition
| First step, acetyl-CoA -> malonyl-CoA |
|
|
Term
| acetyl CoA carboxylase is inhibited by ______ |
|
Definition
| palmitoyl-CoA, the eventual product (downregulates synthesis when there is an excess of free fatty acids) |
|
|
Term
| acetyl CoA carboxylase is stimulated by _____ |
|
Definition
| citrate (to ensure that fatty acid synthesis proceeds in the fed state) |
|
|
Term
| What stimulates the kinase that phosphorylates and deactivates acetyl CoA carboxylase? |
|
Definition
|
|
Term
| How does insulin affect acetyl CoA carboxylase? |
|
Definition
| It stimulates PP2A which dephosphorylates and therefore activates acetyl CoA carboxylase |
|
|
Term
| What does the presence of high concentrations of citrate in the cytoplasm indicate? |
|
Definition
| We are making fat! Citrate in the cytoplasm is broken down into acetyl-CoA for fatty acid synthesis |
|
|
Term
| Epinephrine and glucagon affect on acetyl CoA carboxylase? |
|
Definition
| inhibits PP2A -> inactivates acetyl-CoA carboxylase (Insulin stimulates it) |
|
|
Term
| Is the phosphorylated form of acetyl CoA carboxylase active or inactive? |
|
Definition
|
|
Term
| Initiation of the synthesis of a new fatty acid molecule involves binding of _____ & ______ to the Fatty acid synthase complex. |
|
Definition
| acetyl-CoA and Malonyl-CoA |
|
|
Term
| After acetyl-CoA and Malonyl-CoA is bound to the Fatty acid synthase complex, acetyl-CoA is transferred onto the _____ (the _____ _____ carbon is ridded of via decarboxylation to produce carbon dioxide). |
|
Definition
malonyl-CoA
malonyl-CoA’s 3rd |
|
|
Term
| After acetyl-CoA and Malonyl-CoA is bound to the Fatty acid synthase complex, acetyl-CoA is transferred onto the malonyl-CoA(the malonyl-CoA’s 3rd carbon is ridded of via decarboxylation to produce carbon dioxide). So, you end up with a four-carbon chain with two ____ groups, called ______ |
|
Definition
|
|
Term
| What vitamin is found in both CoA and the acyl carrier protein? |
|
Definition
| Panthothenic acid (B vitamin) |
|
|
Term
| What enzyme complex in FA synthesis contains the acyl carrier protein? |
|
Definition
|
|
Term
| What is the primary role of the acyl carrier protein (ACP) in FA synthesis? |
|
Definition
| Binds growing chain during synthesis |
|
|
Term
| What happens to the CO2 that is added to acetyl CoA by acetyl CoA carboxylase? |
|
Definition
| Knocked off when acyl-CoA binds to malonyl-CoA |
|
|
Term
| Identify the cofactor that reduces the 3-ketoacyl group on the elongating chain that is attached to the ACP |
|
Definition
|
|
Term
| After the decarboxylation following the attachment of Acetyl-CoA to Malonyl-CoA you end up with two keto groups, the ____ keto group is fully _____, and the chain is translocated to the other site, from which it will eventually be translocated onto a new ______. |
|
Definition
distal
reduced
Malonyl-CoA |
|
|
Term
| Elongation system of FA Synthesis adds _____ carbons at a time through the addition of ______. |
|
Definition
|
|
Term
| Cycle of FA synthesis continues until a ______ is produced |
|
Definition
|
|
Term
| Cycle of FA synthesis continues until a 16-C (palmityl-ACP) is produced, after which ____ cleaves off the ACP, leaving palmitate and ACP as final products |
|
Definition
|
|
Term
| How is acetyl-CoA transported from the mitochondria into the cytoplasm? |
|
Definition
| It is combined with Oxaloacetate to form citrate by citrate synthase |
|
|
Term
| How is acetyl-CoA transported from the cytoplasm into the mitochondria? |
|
Definition
| Citrate is reconverted into OAA and acetyl-CoA by ATP-citrate lyase (uses an ATP) |
|
|
Term
| Can OAA cross the MT membrane? |
|
Definition
|
|
Term
Cycling of OAA:
OAA and Acetyl-CoA are combined to form _______ by _____ in the MT matrix, which is then shuttled across the MT membrane. In the cytoplasm ______ is then broken down back into OAA and Acetyl CoA by the enzyme ______, which requires ______. Acetyl-CoA is then used in ______, while OAA is then reduced into ______ by the _____ enzyme by oxidizing _____ in the process. |
|
Definition
Cycling of OAA:
OAA and Acetyl-CoA are combined to form Citrate by Citrate Synthase in the MT matrix, which is then shuttled across the MT membrane. In the cytoplasm citrate is then broken down back into OAA and Acetyl CoA by the enzyme ATP-Citrate Lyase, which requires ATP. Acetyl-CoA is then used in Fatty Acid Synthesis, while OAA is then reduced into malate by the malate DH enzyme by oxidizing NADH in the process. |
|
|
Term
Cycling of OAA:
OAA and Acetyl-CoA are combined to form Citrate by Citrate Synthase in the MT matrix, which is then shuttled across the MT membrane. In the cytoplasm citrate is then broken down back into OAA and Acetyl CoA by the enzyme ATP-Citrate Lyase, which requires ATP. Acetyl-CoA is then used in Fatty Acid Synthesis, while OAA is then reduced into malate by the malate DH enzyme by oxidizing NADH in the process. Malate can then be transported directly back into the MT Matrix and then oxidized into _____ by ______ through the reduction of ______... |
|
Definition
|
|
Term
Cycling of OAA:
OAA and Acetyl-CoA are combined to form Citrate by Citrate Synthase in the MT matrix, which is then shuttled across the MT membrane. In the cytoplasm citrate is then broken down back into OAA and Acetyl CoA by the enzyme ATP-Citrate Lyase, which requires ATP. Acetyl-CoA is then used in Fatty Acid Synthesis, while OAA is then reduced into malate by the malate DH enzyme by oxidizing NADH in the process. Malate can then be transported directly back into the MT Matrix and then oxidized into Malate by Malate DH through the reduction of NADH, or it can remain in the cytoplasm and be converted into _____ by _____ enzyme, which results in the formation of ____ & _____ byproducts, one of which goes to be used in _______. |
|
Definition
pyruvate
Malic Enzyme
NADPH and CO2
NADPH FA Synthesis |
|
|
Term
| Pyruvate can be converted into OAA by _____ enzyme that uses ____ & _____. |
|
Definition
Pyruvate Carboxylase
CO2 and ATP |
|
|
Term
| In the cycling of OAA for Fatty Acid Synthesis, which enzyme has a cytoplasmic and mitochondrial form? |
|
Definition
|
|
Term
Malate DH:
Reaction in mitochondria?
Reaction in Cytoplasm? |
|
Definition
| In mitochondria, malate -> OAA (NAD+ -> NADH) In cytoplasm, OAA -> malate (NADH -> NAD+) |
|
|
Term
| In the cycling of OAA for Fatty Acid Synthesis what enzyme requires NADP+ as a cofactor? |
|
Definition
Malic Enzyme
Malate NADP+ -> Pyruvate + CO2 and NADPH |
|
|
Term
| In the cycling of OAA for Fatty Acid Synthesis what enzyme requires NAD+ as a cofactor? |
|
Definition
|
|
Term
| What is the source of carbons for building fatty acids? |
|
Definition
|
|
Term
| Where does fatty acid synthesis occur? |
|
Definition
|
|
Term
| Where does beta oxidation of FFA occur? |
|
Definition
|
|
Term
| So, acetyl-CoA is made in the mitochondria, but fatty acid synthesis occurs in the cytoplasm. That’s why we need _____ to bring it across. |
|
Definition
|
|
Term
| _______ elongate past 16C (palmitate) |
|
Definition
|
|
Term
| _____ system of fatty acid elongation prefers fewer than 16 C |
|
Definition
|
|
Term
| Fatty acids are elongated at ____C per time. |
|
Definition
|
|
Term
| _______ donates carbons for fatty acid elongation in mitochondria |
|
Definition
|
|
Term
| _____ donates carbons for fatty acid elongation in the ER. |
|
Definition
|
|
Term
| What is the final product of fatty acid synthase? |
|
Definition
|
|
Term
| What is the fatty acid that results from Palmitate's elongation called? |
|
Definition
|
|
Term
| Hexadecanoic acid = ______ |
|
Definition
| has 16 carbons (palmitic acid). |
|
|
Term
| What products do you get when you desaturate palmitate? |
|
Definition
|
|
Term
| What products do you get when you desaturate Stearate? |
|
Definition
|
|
Term
| What enzyme desaturates palmitate and stearate? |
|
Definition
|
|
Term
| In the desaturation of palmitate & Stearate into palmitoleic & oleic acid respectively, where is the double bond added by desaturase? |
|
Definition
|
|
Term
| Could we make arachidonate (5,8,11,14), if we were deficient in linoleic acid (18:2;9,12)? |
|
Definition
| No. We can’t add double bonds past Δ9. |
|
|
Term
| List the five major components of lipoprotein particles: |
|
Definition
- Phospholipid (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, sphingomyelin)
- Free cholesterol
-Cholesterol ester
- Triglycerides
- Apolipoprotein |
|
|
Term
| What is the protein component of lipoproteins called? |
|
Definition
|
|
Term
| Apoproteins regulate ____enzymes in the blood |
|
Definition
|
|
Term
| Apoproteins facilitate the transfer of lipids between ______ and between lipoproteins and cells. |
|
Definition
|
|
Term
| Apoproteins mediate the ____ of lipoproteins by binding to ________. |
|
Definition
endocytosis
cell surface receptors |
|
|
Term
| List the functions of the apoproteins found in lipoprotein particles. |
|
Definition
-Structural
- Receptor binding
- Lipase activation
- Lipid transfer |
|
|
Term
| Order the lipoprotein particles by density |
|
Definition
| Density: α-lipoproteins (HDL) > β-lipoproteins (LDL) > pre-β-lipoproteins (VLDL) > chylomicrons |
|
|
Term
| Which class of lipoproteins migrates the fastest toward the anode (positive) and how does its density compare with the rest of the lipoproteins? |
|
Definition
| HDL (α-lipoproteins). Most dense. |
|
|
Term
| Pre-beta lipoproteins = ____ lipoprotein |
|
Definition
|
|
Term
| Beta-lipoproteins = ____ lipoprotein |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What increases density of lipoproteins? |
|
Definition
|
|
Term
| What is the major role of chylomicrons? |
|
Definition
|
|
Term
| chylomicrons are present when? |
|
Definition
|
|
Term
| ____ are the precursors of LDL |
|
Definition
|
|
Term
| What is the origin of IDL particles? |
|
Definition
|
|
Term
| What is the major role of the VLDL particles? |
|
Definition
| Lipids synthesized by liver and released as VLDL. Precursor of LDL. |
|
|
Term
| What is the origin of LDL particles? and what action is required for this? |
|
Definition
VLDL -> IDL -> LDL
(requires hydrolysis of excess triglyceride and phospholipid by hepatic lipase) |
|
|
Term
|
Definition
| Activates lechithin-cholestrol acyltransferase in HDL |
|
|
Term
| Apoprotein B-48 Function? |
|
Definition
| Structural portein for chylomicrons |
|
|
Term
| Apoprotein B-100 function? |
|
Definition
structural protein for VLDL and LDL
Contains LDL receptor binding domain |
|
|
Term
| Apoprotein C-II function? |
|
Definition
| activates extrahepatic lipoprotein lipase |
|
|
Term
|
Definition
| Mediates uptake of chylomicron remnants by the liver |
|
|
Term
|
Definition
|
|
Term
| Where is Apo B-100 found? |
|
Definition
|
|
Term
| Apo B-100 has a LDL receptor-binding domain that is responsible for __________ |
|
Definition
| attaching to peripheral tissue and unloading cholesterol |
|
|
Term
| What function does Apo B-100 have that Apo B-48 doesn’t have? |
|
Definition
| Apo B-100 serves as a structural protein for VLDL and LDL instead of chylomicrons. Most importantly, B-100 contains LDL-receptor binding domain. |
|
|
Term
| How does the extra function of Apo B-100 correlate with its role in delivering cholesterol to the tissues? |
|
Definition
| Contains LDL-receptor binding domain. Most of LDL ends up hydrolyzed by the liver, but in extrahepatic tissues, LDL receptor is the major external source of cholesterol. |
|
|
Term
| Which lipoprotein particles receive the Apo E? |
|
Definition
|
|
Term
| Which receptor binds Apo E? |
|
Definition
| lipoprotein receptors including the LDL receptor |
|
|
Term
| After triglycerides are synthesized, they are assembled into chylomicrons in the ___ of an ______ cell with only ________ apoproteins. |
|
Definition
ER
intestinal mucosal
only A and B48 apoproteins |
|
|
Term
| What is the only apoprotein not associated with chylomicrons? |
|
Definition
|
|
Term
| After the chylomicron is released from the intestinal mucosal cell with apoproteins A and B48 into the _______ and eventually into the blood, in the blood it receives _____ apoproteins from ______. |
|
Definition
|
|
Term
| When a chylomicron (apo A, B48, C, E) gets to an endothelial cell of a capillary _____ removes _______. This activity depends on _____ |
|
Definition
LPL (lipoprotein lipase)
triglycerides
LPL activity depends on apoCII on surface of chylomicron. |
|
|
Term
| LPL activity depends on _____ on surface of chylomicron. |
|
Definition
|
|
Term
| After the chylomicron's TG have been removed by LPL at the endotheial cells, the now _______ receives ____ & _____ from _______ & gives up: ______ to _____. |
|
Definition
Chylomicron Remnant
ApoE and Cholestrol Esters from HDL
apoC, phospholipids, and cholesterol to HDL. |
|
|
Term
| After the chylomicron remnant has traded with HDL it then binds to lipoprotein receptors by Apo_ and is uptaken by the _____. |
|
Definition
|
|
Term
| Origin of Apo C & E for chylomicrons |
|
Definition
C & E in blood the blood from HDL
C before delivery, E after deliver of TG |
|
|
Term
|
Definition
| Extrahepatic Lipase (Needed to hyrdolyze the TG off of chylomicrons at the endothelial cells in the blood) |
|
|
Term
| Chylomicron remnants are the result of hydrolyzation of chylomicrons by ______ |
|
Definition
|
|
Term
| One more time, what is the role of Apo E? |
|
Definition
| facilitates binding and uptake of remnants by the liver |
|
|
Term
| VLDL are synthesized by the liver and can be processed by ____ into LDL so that is can go to ______ |
|
Definition
|
|
Term
| VLDL can be rebound by the ____ and endocytosed |
|
Definition
|
|
Term
| Where do the fatty acids that make up the VLDL normally come from? |
|
Definition
|
|
Term
| Where do the cholesterol esters come from? |
|
Definition
| HDL (Given to Chylomicron Remnants) |
|
|
Term
| lecithin:cholesterol acyl transferase (LCAT) binds to the surface of ____ where it becomes activated by ______. |
|
Definition
|
|
Term
| Lecithin:cholesterol acyl transferase (LCAT) catalyzes what reaction? |
|
Definition
| Cholesterol + Phosphatidylcholine -> cholesterol ester + 2-lysophosphatidylcholine (lysolecithin) |
|
|
Term
| 2-lysophosphatidylcholine (lysolecithin) a product of Lecithin:cholesterol acyl transferase (LCAT) is transferred to _____, while the other product cholestrol ester is ______. |
|
Definition
albumin
goes to the center of HDL |
|
|
Term
| How is the acyl CoA:cholesterol acyl transferase (ACAT) enzyme different from the LCAT? |
|
Definition
Acyl CoA:cholesterol acyl transferase (ACAT) Catalyzes: cholesterol + acyl-CoA -> cholesterol ester + CoA-SH
Source of fatty acid is different (acyl-CoA vs. phosphatidylcholine). Also, ACAT is inside cell tissue |
|
|
Term
| Where are ACAT and LCAT found? |
|
Definition
LCAT: attached to HDL in bloodstream
ACAT: intracellular. ER |
|
|
Term
| Cholesterol in HDL can either be _____ via _____ and go to the center of HDL or can be transfered to other lipoproteins and remnants in exchange for ______, and eventually go to the liver via ________. |
|
Definition
esterified via LCAT
TG
via cholesterol ester transfer protein CETP |
|
|
Term
| During HDL maturation, it becomes ____ shaped |
|
Definition
|
|
Term
| During HDL maturation LCAT makes ______ and ______ from cholesterol and phosphatidylcholine. |
|
Definition
cholesterol ester
lysolecithin |
|
|
Term
| During HDL maturation cholesterol esters_____. |
|
Definition
|
|
Term
|
Definition
| Contains phospholipids, cholesterol esters, cholesterol, and trigylcerides, along with apoE, apoA’s, apoC’s, CETP, and LCAT on the surface |
|
|
Term
| What kind of interchange occurs between HDL particles and VLDL and chylomicron particles? |
|
Definition
| Give cholesterol esters alone or in exchange for triglycerides. Also gives them lipoproteins (apoC and apoE). |
|
|
Term
| What is the term for immature HDL? |
|
Definition
|
|
Term
| During triglyceride hydrolysis, VLDL transfers: _________ to HDL. |
|
Definition
| triglycerides, phospholipids, apoC, and some apoE |
|
|
Term
| What is the shape of immature HDL? |
|
Definition
|
|
Term
| What are the contents of an immature HDL? |
|
Definition
| apoAI, apoAII, apoE, apo-C’s, phospholipids, and cholesterol |
|
|
Term
| What apoproteins are contained in liver HDL? |
|
Definition
| Liver: apoA-I, apoA-II, apoE, and C-I, II, III. |
|
|
Term
| What apoproteins are contained in intestinal HDL? |
|
Definition
| Intestinal HDL formed with only apoA-I |
|
|
Term
| What enzyme is contained in HDL particles? |
|
Definition
| Lecithin-cholesterol acyl transferase (LCAT) |
|
|
Term
| What functions do HDL particles have? |
|
Definition
Cholesterol transport
giving apoproteins to other lipoproteins |
|
|
Term
| HDL particles deliver cholesterol to ______ or take it back to _____. |
|
Definition
|
|
Term
| In Type I: hyperchylomicronemia, _____ is elevated in the plasma and there is a deficiency of ______. |
|
Definition
TG
lipoprotein lipase (LPL) or apo CII |
|
|
Term
| In Type II: hypercholesterolemia, _____ is elevated in the plasma and there is a deficiency of ______. |
|
Definition
- LDL elevated
- LDL receptor deficiency or secondary causes (diabetes, obesity, hypothyroidism, baby back ribs) |
|
|
Term
| In Type III: dysbetalipoproteinemia also known as ________, results from a genetic _______ and has elevated ______. |
|
Definition
| dysbetalipoproteinemia; homozygous recessive apoE2 (elevated remnants) |
|
|
Term
| Which type of hyperlipoproteinemias has the highest risk of coronary heart disease? |
|
Definition
II
Type II: hypercholesterolemia - LDL elevated - LDL receptor deficiency or secondary causes (diabetes, obesity, hypothyroidism, baby back ribs) |
|
|
Term
| Type I hyperlipoproteinemia stems from impaired hydrolysis of _______ |
|
Definition
chylomicron triglycerides (Deficiencies of lipoprotein lipase or apo CII)
Type I (hyperchylomicronemia) |
|
|
Term
| Familial hypercholesterolemia is what type of hyperlipoproteinemias? |
|
Definition
|
|
Term
| People with Familial Hypercholesterolemia (Type II) have elevated _____ |
|
Definition
|
|
Term
| Type I hyperlipoproteinemias is _____ |
|
Definition
|
|
Term
| Type II hyperlipoproteinemias is _____ |
|
Definition
|
|
Term
| Type III hyperlipoproteinemias is _____ |
|
Definition
|
|
Term
| Type II hyperlipoproteinemia (Familial hypercholesterolemia) has elevated _____ |
|
Definition
|
|
Term
| Type II hyperlipoproteinemia (Familial hypercholesterolemia) heterozygots have 2x normal ______, because of _____ synthesis is stimulated. Homozygotes are dead by ____ |
|
Definition
LDL
Endogenous Cholestrol
20 |
|
|
Term
| Type II hyperlipoproteinemia (Familial hypercholesterolemia) patients are at risk for ______ |
|
Definition
|
|
Term
| What is a characteristic of both homo and heterozygotes of Type II hyperlipoproteinemia (Familial hypercholesterolemia)? |
|
Definition
| Xanthomas (subcutaneous yellow lipid deposits) |
|
|
Term
| The defect associated with Type III hyperlipoproteinemia is impaired homozygous for ______, which results in elevated _____ |
|
Definition
(Type III: dysbetalipoproteinemia)
recessive apoE2
remnants |
|
|
Term
| What is elevated in Type I hyperlipoproteinemia? |
|
Definition
|
|
Term
| What is elevated in Type II hyperlipoproteinemia? |
|
Definition
|
|
Term
| What is elevated in Type III hyperlipoproteinemia? |
|
Definition
|
|
Term
| Gluconeogenesis is the Synthesis of glucose from: _______. |
|
Definition
| amino acids, lactate, and glycerol. |
|
|
Term
| Is the Breakdown of glycogen gluconeogenesis? |
|
Definition
|
|
Term
| non-glucose precursors for gluconeogenesis means what? |
|
Definition
| The carbons that contribute to glucose can come from amino, acids, lactate, and glycerol. NOT glycogen for gluconeogenesis. |
|
|
Term
| Glucose -> G6P by hexokinase is bypassed in gluconeogenesis by _____ |
|
Definition
| Glucose-6-phosphatase: Glucose-6-phosphate -> Glucose [irreversible] |
|
|
Term
| Fructose-6-phosphate -> Fructose-1,6-bisphosphate by PFK is bypassed in gluconeogenesis by _____ |
|
Definition
| Fructose-1,6-bisphosphatase: Fructose-1,6-bisphosphate -> Fructose-6-phosphate [irreversible] |
|
|
Term
| PEP -> Pyruvate by pyruvate kinase is bypassed in gluconeogenesis by _____ |
|
Definition
1. Pyruvate to OAA by Pyruvate Carboxylase using ATP to ADP
2. OAA to PEP by PEP-Carboxylase using GTP to GDP |
|
|
Term
| How many high energy bonds are required per glucose synthesized? |
|
Definition
6ATP/GTP and 2 NADH
2 ATP – pyruvate carboxylase
2 GTP – PEP carboxykinase
2 ATP – phosphoglycerate kinase (3-phosphoglycerate -> 1,3 bisphosphoglycerate) |
|
|
Term
| Enzyme that bypasses the hexokinase reaction? |
|
Definition
|
|
Term
| Where is Glucose-6-phosphatase found? |
|
Definition
| The liver and kidneys only, not in the skeletal muscle |
|
|
Term
| Why is Glucose-6-phosphatase not found in skeletal muscle? |
|
Definition
| Skeletal muscle regenerates glucose through glycogen breakdown |
|
|
Term
| Name the enzyme that bypasses the phosphofructokinase? |
|
Definition
| Fructose-1,6-bisphosphatase |
|
|
Term
| ATP affect on PFK and phosphofructokinase? |
|
Definition
Stimulates phosphofructokinase
Inhibits PFK |
|
|
Term
| Citrates affect on PFK and phosphofructokinase? |
|
Definition
Stimulates phosphofructokinase
Inhibits PFK |
|
|
Term
| Fructose-2,6-bisphosphate activates ____ and is a competitive inhibitor of ______. |
|
Definition
PFK
fructose-1,6-bisphosphatase |
|
|
Term
| With respect to Fructose-2,6-bisphosphate and PFK; Insulin elevates level of _____, stimulates _____, inhibits _____. |
|
Definition
|
|
Term
| Glucagon _____ PFK/glycolysis, ____ F-1,6-BP |
|
Definition
|
|
Term
| What is meant by reciprocal regulation? |
|
Definition
| Stimulators in one direction will be inhibitors in the other, and vice versa, to prevent futile cycle. |
|
|
Term
| What allosteric effectors stimulate PFK? |
|
Definition
| Fructose-2,6-bisphosphate. |
|
|
Term
| What allosteric effectors inhibit PFK? |
|
Definition
|
|
Term
| Which of the PFK allosteric effectors is the most important? |
|
Definition
| Fructose-2,6-bisphosphate. Insulin and glucagon stimulate and inhibit PFK through this. |
|
|
Term
| Give the two reactions that convert pyruvate back into PEP. |
|
Definition
- Pyruvate -> OAA via pyruvate carboxylase (ATP->ADP)
- OAA -> PEP via PEP carboxykinase (GTP -> GDP) |
|
|
Term
| The first step of gluconeogenesis: Pyruvate -> OAA via pyruvate carboxylase (ATP->ADP) is activated and inhibited by? |
|
Definition
Acetyl CoA
its product ADP |
|
|
Term
| What vitamin cofactor does pyruvate carboxylase require? |
|
Definition
|
|
Term
| pyruvate carboxylase requires biotin in order to bind ____ and transfer it to _____. |
|
Definition
|
|
Term
| PEP -> pyruvate is inhibited during glycolysis by _______. |
|
Definition
|
|
Term
| PEP -> pyruvate is activated during glycolysis by ________. |
|
Definition
| fructose-1,6-bisphosphate (feedforward stimulation) |
|
|
Term
| OAA -> PEP via PEP carboxykinase requires _____ as an energy source and gives off _____ as a byproduct. |
|
Definition
GTP to GDP
CO2 (CO2 added in previous step by pyruvate carboxylase) |
|
|
Term
| PEP-carboxykinase reaction takes place in the _____. |
|
Definition
|
|
Term
| Pyruvate carboxylase reaction takes place in the _____. |
|
Definition
|
|
Term
| Give the gluconeogenic step that requires NADH. |
|
Definition
| 1,3-bisphosphoglycerate -> glyceraldehyde-3-phosphate (Produces NADH in glycolysis) |
|
|
Term
| Lactate is converted to ____ by _____ to provide the carbon skeleton for gluconeogenesis. |
|
Definition
|
|
Term
| Alanine is converted to ____ by _____ to provide the carbon skeleton for gluconeogenesis. |
|
Definition
|
|
Term
| Amino Acids other than Alanine are converted to ____ to provide the carbon skeleton for gluconeogenesis. |
|
Definition
| OAA through the TCA Cycle |
|
|
Term
| Glycerol for gluconeogenesis come from ____ tissue. |
|
Definition
|
|
Term
| Glycerol enters the gluconeogenic pathway at the level of _____. |
|
Definition
|
|
Term
| Glycerol is converted into _____ by the enzyme _____, which is only found in the _____, in order to enter the gluconeogenic pathway. |
|
Definition
Glycerol 3P (NOT Glyceraldehyde-3-P as seen in Glycolysis)
glycerol kinase
found ONLY in liver |
|
|
Term
| Glycerol kinase is only found in ______ |
|
Definition
|
|
Term
| After glycerol kinase has converted glycerol into G3P in order to prep it for gluconeogenesis it is then converted into ________, by _______ producing _____ in the process. |
|
Definition
DHAP
Glycerol Phosphate DH
NAD+ -> NADH |
|
|
Term
| Glycerol enters the gluconeogenic pathway as ______. |
|
Definition
|
|
Term
| Glycerol Kinase converts Glycerol to G3P in the liver, consuming ____ in the process. |
|
Definition
|
|
Term
| Where is glycerol kinase found? |
|
Definition
|
|
Term
| Is Acetyl CoA a source of OAA for gluconeogenesis? |
|
Definition
|
|
Term
| _____ is a bifunctional enzyme. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| PFK-2 kinase activity phosphorylates ______, which produces ______. |
|
Definition
|
|
Term
| PFK-2 kinase activity phosphorylates F-6-P, which produces F-2,6-P. This increases the rate of ______. |
|
Definition
|
|
Term
| PFK-2 Phosphatase activity dephosphorylates ____, producing ______. |
|
Definition
|
|
Term
| PFK-2 Phosphatase activity dephosphorylates F-2,6-P, producing F-6-P, which then eventually goes on ______ |
|
Definition
| through glycolysis to become F-1,6-P |
|
|
Term
| Dephosphorylated PFK2 is a ______. |
|
Definition
|
|
Term
| What hormone stimulates the phosphorylation of PFK-2. |
|
Definition
|
|
Term
| What hormone stimulates the dephosphorylation of PFK-2. |
|
Definition
|
|
Term
| Dephosphorylated PFK-2 is a _____. |
|
Definition
|
|
Term
| Glucagon _____ [F-2,6-BP] |
|
Definition
|
|
Term
| Insulin ______ [F-2,6-BP] |
|
Definition
|
|
Term
| Phosphorylated PFK-2 is a _____. |
|
Definition
|
|
Term
| PFK-2 is phosphorylated in response to _____ |
|
Definition
|
|
Term
| PFK-2 is dephosphorylated in response to _____ |
|
Definition
|
|
Term
| What effect does glucagon have on the formation of cAMP? |
|
Definition
| Glucagon increases cellular cAMP |
|
|
Term
| PFK-2 is phosphorylated by the _____activated protein kinase ____ in response to _____. |
|
Definition
|
|
Term
| What effect does cAMP have on PFK-2 activity? |
|
Definition
|
|
Term
| Less fructose 2,6-bisphosphate creates more F6P, driving the reaction in the ____ way. |
|
Definition
|
|
Term
| Give the tissues that contain the gluconeogenic pathway |
|
Definition
| Liver, kidney (less significant) |
|
|
Term
| Does skeletal muscle make and release glucose? |
|
Definition
| Glucose is made, but immediately rephosphorylated and used for glycolysis. NOT released into the bloodstream (as in liver). |
|
|
Term
| Is glycogen branched or linear? |
|
Definition
|
|
Term
| Glycogen has branches every ____ residues. |
|
Definition
|
|
Term
| glycogen is held together with _____ bonds and its branch points are formed by _____ bonds. |
|
Definition
α-1,4 glycosidic bonds
α-1,6 glycosidic bonds |
|
|
Term
| Glycogenin attached to the _____ of glycogen. |
|
Definition
|
|
Term
| What is the osmotic advantage of glycogen? |
|
Definition
| If you were to simply store free glucose molecules in the cell, the osmotic gradient created would cause the cell to suck up water like a “delirious camel,” and eventually cause it to burst. By using polymers (glycogen), you effectively eliminate this problem. |
|
|
Term
| Which ends of the glycogen molecule give a reaction with Fehling’s solution? |
|
Definition
|
|
Term
| Exactly which bonds are the glycosidic bonds? |
|
Definition
| Acetal or ketal bonds involving the anomeric carbon of one of the participating monosaccharides. Bonds between each glucose residue. |
|
|
Term
| Explain the role of glycogenin in limiting the size of glycogen molecules. |
|
Definition
| Glycogen synthase adds the glucose residues, but it must always be in contact with glycogenin. Eventually, a size is reached where that can no longer occur. Glycogenin determines the total number of glycogen molecules. |
|
|
Term
|
Definition
| Glycogenin is an enzyme involved in converting glucose to glycogen. It acts as a primer, by polymerizing the first few glucose molecules, after which other enzymes take over |
|
|
Term
| Explain the term “reducing sugar.” |
|
Definition
| Carbonyl carbon has reducing properties, which are lost when carbon (usually anomeric carbon 1) forms glycosidic bond. Conventionally, nonreducing end is written on the left and reducing on the right. |
|
|
Term
| Starch structure, linear or branched? |
|
Definition
|
|
Term
|
Definition
| α-1,4 glycosidic bonds (same as glycogen) |
|
|
Term
| Glycogen synthesis uses _ high energy phosphate bonds per glucose |
|
Definition
| 2 (1 ATP for hexokinase rxn, and 1 UTP for creation of UDP glucose. |
|
|
Term
| 1) Synthesis of UDP-glucose (activation) for glycogen synthesis steps: ______ |
|
Definition
- Glucose-6P -> Glucose-1P (via phosphoglucomutase)
- Glucose-1P -> UDP-glucose (via UDP-glucose pyrophosphorylase; UTP) **IRREVERSIBLE
- Pyrophosphate 2Pi |
|
|
Term
| Glycogen Synthase (Polymerization Step, Linear Bond Formation) reactions: _______ |
|
Definition
1. UDP-glucose + Glycogen{n} -> Glycogen{n+1} + UDP (via glycogen synthase) creating a α-1,4 glycosidic bond
2. UDP +ATP -> UTP + ADP (Regenerating UTP for the 1st step, activation) |
|
|
Term
| What is the product of the phosphoglucomutase reaction in the direction of glycogen synthesis? |
|
Definition
|
|
Term
| What are the products of the UDP-glucose pyrophosphorylase reaction? |
|
Definition
| Glucose-1P -> UDP-glucose. Pyrophosphate breaks off as 2 free Pi |
|
|
Term
| Glycogen synthase uses ____ as a precursor for glycogen polymerization. |
|
Definition
|
|
Term
| Glycogen synthase transfers glucose from UDP-glucose to 4-hydroxyl group at ____ end. |
|
Definition
|
|
Term
| What are the products of the polymerization reaction of Glycogen Synthesis? |
|
Definition
|
|
Term
| What type of glycosidic bond is formed by glycogen synthetase? |
|
Definition
|
|
Term
| What type of glycosidic bond is formed by branching enzyme? |
|
Definition
|
|
Term
| Does branching occur at the same site that glycogen synthetase is acting (i.e. the end of the chain)? |
|
Definition
|
|
Term
| Branching Enzyme transfers a string of about 7 glucose residues from the end of an unbranched chain to ___ of a glucose residue in a more interior location |
|
Definition
|
|
Term
| About how many glucose residues are involved in starting a branch? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Glycogenolysis uses _____ to cleave a glucose residue from the _____ end of glycogen. |
|
Definition
inorganic phosphate
nonreducing |
|
|
Term
| Glycogenolysis Does or does not cleave the α-1,6 glycosidic bonds at the branch points? |
|
Definition
|
|
Term
| Glycogen Phosphorylase stops ____ residues before a branch. At this point the ____ enzyme takes over. |
|
Definition
|
|
Term
| The debranching enzyme transfers a block of __ glucose residues from the end of the chain to the C_____ end of another chain. |
|
Definition
|
|
Term
| The debranching enzyme transfers a block of 3 glucose residues from the end of the chain to the C4 end of another chain. Leaving one glucose molecule at the branch point which is then ______ |
|
Definition
|
|
Term
| Debranching enzyme has 2 activities, ___ & _____. |
|
Definition
transferase
hydrolase (glucosidase) |
|
|
Term
| What are the two products of the glycogen phosphorylase reaction? |
|
Definition
| Glucose-1-phosphate and the rest of glycogen chain |
|
|
Term
| What happens to the glucose 1-phosphate produced by the glycogen phosphorylase reaction? |
|
Definition
| Glucose-1-phosphate can be converted to UDP-glucose for glycogen synthesis or it can be converted to G-6-P and enter glycolysis in the muscle or make glucose to be released in the liver (catalyzed by glucose-6-phosphatase). |
|
|
Term
| Does glycogen phosphorylase act on reducing ends or nonreducing ends? |
|
Definition
|
|
Term
| What is the product of the transferase step of debranching enzyme action? |
|
Definition
| Linear chain elongated by 3C and one glucose left where the branch was |
|
|
Term
| What is the product of the Glucosidase step of debranching enzyme action? |
|
Definition
| Linear chain and 1 free glucose |
|
|
Term
| glycogen metabolism activation? |
|
Definition
epinphrine causes cAMP to be produced
cAMP converts protein kinase A to active form
Phosphorylates phosphorylase kinase b and turns it into active phosphorylase kinase a, which phosphorylates phosphorylase and makes it active |
|
|
Term
| Glycogen synthase is _____ in dephosphorylated state |
|
Definition
|
|
Term
| Glycogen phosphorylase is ____ in phosphorylated state |
|
Definition
|
|
Term
| Protein Kinase A _____ glycogen phosphorylase |
|
Definition
|
|
Term
| Protein Kinase A _____ glycogen synthase |
|
Definition
|
|
Term
| G6P ____ glycogen synthase. |
|
Definition
|
|
Term
| Protein phosphatase 1 affect on glycogen synthase/ phosphorylase? |
|
Definition
glycogen synthase- stimulates
glycogen phosphorylase- inhibits |
|
|
Term
| Insulin: ____ glycogen synthesis in ______ |
|
Definition
stimulates
liver and skeletal muscle |
|
|
Term
| Insulin: _____ protein phosphatase 1 |
|
Definition
|
|
Term
| Glucagon: ____ protein kinase A by _____. |
|
Definition
Stimulate
phosphorylating it. |
|
|
Term
| Glucagon: _____ glycogen degradation in ______. |
|
Definition
Stimulates
liver but NOT MUSCLE |
|
|
Term
| Is phospho-glycogen synthase fully active or less active? |
|
Definition
|
|
Term
| Is phospho-phosphorylase fully active or less active? |
|
Definition
|
|
Term
| What is the effect of insulin on cAMP concentrations? |
|
Definition
|
|
Term
| What tissue responds to epinephrine? |
|
Definition
| muscle and liver (mostly muscle) |
|
|
Term
| What tissue responds to Glucagon? |
|
Definition
|
|
Term
| What is the effect of increased cAMP concentrations? |
|
Definition
| Increased cAMP: activated protein kinase A -> inactivation of glycogen synthase -> activation of glycogen phosphorylase |
|
|
Term
| What is the effect of reduced cAMP concentrations? |
|
Definition
| Decreased cAMP: deactivated protein kinase A -> activation of glycogen synthase -> deactivation of glycogen phosphorylase |
|
|
Term
| In ____ disease trapped glucose6-phosphate affects multiple pathways |
|
Definition
|
|
Term
| Resulting Hypoglycemia from Von Gierke’s ____ insulin and ____ glucagon. |
|
Definition
|
|
Term
| Gluconeogenesis is _____ in Von Gierke’s |
|
Definition
|
|
Term
| In Von Gierke’s Pyruvate shunted to _____ |
|
Definition
|
|
Term
| Defficient enzyme in Von Gierke’s |
|
Definition
|
|
Term
| In Von Gierke’s inactive form of glycogen synthase is stimulated by excess _____. |
|
Definition
|
|
Term
| What enzyme if deficient in Cori’s disease? |
|
Definition
|
|
Term
| Cori’s disease limited amount of glucose is available beyond _____. |
|
Definition
|
|
Term
| What enzyme if deficient in Andersen’s disease? |
|
Definition
|
|
Term
| Andersen’s disease results in ______. |
|
Definition
Unbranched long chains (amylopectin) cause cirrhosis
(Deficient branching enzyme) |
|
|
Term
| Glycogen is turned over in _____ |
|
Definition
|
|
Term
| Pompe’s disease is deficient in? |
|
Definition
| α-1,4-glucosidase (“acid maltase”) for the lysosome |
|
|
Term
| What happens in Pompe’s disease? |
|
Definition
If we don’t break down glycogen in lysosomes, we end up with engorged liver, lysosomes full of glycogen
Death from cardiac failure in infants |
|
|
Term
| What enzyme if deficient in McArdle’s disease? |
|
Definition
|
|
Term
| In McArdle’s disease patients cannot make lactate from _____. |
|
Definition
|
|
Term
| Injection of ____ has no effect In McArdle’s disease. |
|
Definition
|
|
Term
| ____ appears in urine (produced by severe cramping) in McArdle’s disease. |
|
Definition
|
|
Term
| Can make lactate from _____, but not from ______ in McArdle’s disease. |
|
Definition
|
|
Term
| Positive nitrogen balance implies ______, but total _____ is affected |
|
Definition
net protein synthesis
amino acid pool |
|
|
Term
| Positive nitrogen balance is present in what conditions: _______ |
|
Definition
| Recovery from starvation; growth; pregnancy |
|
|
Term
| Negative nitrogen balance: Nitrogen consumed ___ nitrogen excreted |
|
Definition
|
|
Term
| Negative nitrogen balance implies mobilization of _____ |
|
Definition
|
|
Term
| Tissue Necrosis is evident in positive or negative nitrogen balance? |
|
Definition
|
|
Term
| Negative nitrogen balance is present in what conditions: _______ |
|
Definition
| Starvation (kwashiorkor/marasmus), burns, surgery (normal wound healing involves breakdown and synthesis), infection/inflammation |
|
|
Term
| ______ amino acids cannot be produced by the body and must be consumed in the diet. |
|
Definition
|
|
Term
| Non-essential amino acids can be made endogenously by _______. |
|
Definition
|
|
Term
| How is glutamic acid synthesized from alpha-ketoglutarate. |
|
Definition
| Glutamic acid is synthesized from alpha-ketoglutarate by the amination of alpha-keto glutarate |
|
|
Term
| The conversion of glutamic acid to alpha-ketoglutarate is done by what enzyme and requires what cofactor? |
|
Definition
glutamate dehydrogenase
NADPH or NADH
NADP+ or NAD+ in the reverse direction |
|
|
Term
| How is glutamine synthesized from glutamic acid? And requires what? |
|
Definition
Glutamate + ATP + NH3 -> Glutamine + ADP + Pi
glutamine synthetase. Requires ammonia and ATP |
|
|
Term
| What enzyme removes free ammonia from glutamine? |
|
Definition
|
|
Term
| Glutaminase catalyzes what reaction? and requires what? |
|
Definition
Glutamine -> Glutamate and releases ammonia.
water |
|
|
Term
| Alanine is synthesized from _____ by ____ enzyme. |
|
Definition
Pyruvate
Alanine Transaminase |
|
|
Term
| What methyl donor is an intermediate in the pathway for conversion of methionine to cysteine? |
|
Definition
| Methyl donor: S-adenyl methionine (SAM). |
|
|
Term
| What other non-essential amino acid is required for conversion of methionine to cysteine? |
|
Definition
|
|
Term
| What amino acid is a precursor for proline synthesis? |
|
Definition
|
|
Term
| What four carbon citric acid cycle intermediate is transaminated to from aspartate? |
|
Definition
|
|
Term
| What is the nitrogen source for the conversion of aspartate to asparagine? |
|
Definition
|
|
Term
| What is the nitrogen source for the conversion of glutamate to glutamine? |
|
Definition
|
|
Term
| Asparagine Synthase requires ______. |
|
Definition
| Ammonia and ATP (ATP-ADP) |
|
|
Term
| Gulaminase catalyzes what reaction? |
|
Definition
|
|
Term
| Glutamine Synthase reaction? |
|
Definition
| ATP + NH3 + Glutamate -> ADP + Pi + Glutamine |
|
|
Term
| Conversion of Serine to Glycine reaction? |
|
Definition
| Serine + THF <-> Methylene-THF + Glycine |
|
|
Term
| Is the conversion of serine to glycine reversible? |
|
Definition
|
|
Term
| Conversion of Glycine to Serine? |
|
Definition
| Glycine + Methylene-THF -> Serine + THF |
|
|
Term
| Interconversion of Glycine and Serine provides a route from glycine to pyruvate, because serine is _______. |
|
Definition
| serine is synthesized from and degraded to 3-phosphoglycerate |
|
|
Term
| Interconversion of Glycine and Serine requires what vitamin cofactor? |
|
Definition
| Folate (THF) or its active form methylene-THF |
|
|
Term
| Purpose of amino acid catabolism during fasting? |
|
Definition
- Energy production
- Gluconeogenesis (usually from muscle protein breakdown)
- Production of ketone bodies |
|
|
Term
| What energy producing pathway receives the carbon skeletons of most amino acids? |
|
Definition
|
|
Term
| How is nitrogen removed from amino acids prior to the catabolism of their carbon skeletons? |
|
Definition
|
|
Term
| Transaminases needed to remove nitrogen from most amino acids. The nitrogen is removed from amino acid -> α-keto acid, given to ______ to form ______, and then _____ is acted on by ______ to form ammonia. |
|
Definition
α-ketoglutarate
glutamate
glutamate
glutamate dehydrogenase |
|
|
Term
| Transaminases needed for most amino acids (Nitrogen is removed by amino acid α-keto acid, given to α-ketoglutarate to form glutamate, and then glutamate is acted on by glutamate dehydrogenase to form ammonia. The released ammonia then produces ______ |
|
Definition
|
|
Term
| Most important ammonia-forming reaction is catalyzed by _______. |
|
Definition
|
|
Term
| Which amino acid carries nitrogen from muscle tissue to the liver? |
|
Definition
| Alanine, through alanine cycle |
|
|
Term
| In the alanine cycle: Alanine is converted to glucose in the _____, so it can go back to ____. |
|
Definition
|
|
Term
| In the alanine cycle: Alanine is deaminated in the liver to form _____, the NH3 is then feed into the ______. |
|
Definition
|
|
Term
| In the alanine cycle: Alanine is deaminated in the liver to form Pyruvate, pyruvate is then converted into _____ and then into ______. |
|
Definition
|
|
Term
| In the alanine cycle: In the muscles glucose is converted into G6P and then into Pyruvate, pyruvate is then converted into alanine by ______. |
|
Definition
| Transamination of a BCAA, converting pyruvate into alanine and the BCAA into an BCKA all in the muscle. |
|
|
Term
| In the fasting state, degradation of muscle protein provides the carbon skeletons for liver ________. |
|
Definition
|
|
Term
| The pathway of degradation of BCAAs happens only in the _____. |
|
Definition
|
|
Term
| The BCKA formed by degradation of BCAAs and pyruvate in the muscles throughout the alanine cycle can then be ______, the alanine formed then ______. |
|
Definition
Fed into the TCA Cycle
goes back to the liver to continue the alanine cycle |
|
|
Term
| Which of the TCA cycle intermediates serve as an entry point for amino acid carbons? |
|
Definition
- Pyruvate (not technically a TCA intermediate)
- Acetyl-CoA
- OAA
- α-ketoglutarate
- Succinyl-CoA
- Fumarate |
|
|
Term
| Why is leucine considered to be ketogenic? |
|
Definition
- Can’t feed into TCA cycle
- Makes acetoacetate and acetyl-CoA |
|
|
Term
| What are the purely ketogenic aa? |
|
Definition
|
|
Term
| _____ Amino Acids are ketogenic and glucogenic |
|
Definition
| Isoleucine and 3 aromatics (tyrosine, phenylalanine, tryptophan) are both. |
|
|
Term
| The ketogenic amino acids make ______, which is a ketone body. |
|
Definition
|
|
Term
| What is a glucogenic amino acid? |
|
Definition
- Feeds into TCA cycle or glycolysis
- Can be used for gluconeogenesis |
|
|
Term
| If skeletal muscle is consuming amino acid carbon skeletons for energy, how is all of the extra nitrogen disposed of? |
|
Definition
| Goes to the liver on alanine through the alinine cycle, through urea cycle, and excreted in the urine. |
|
|
Term
|
Definition
| YES. Nonessential and glucogenic. |
|
|
Term
| Glutamate dehydrogenase Takes NH3 off glutamate to turn it into _____ it then uses H2O & the conversion of _________ to then release NH4+, a process known as ______ |
|
Definition
α-ketoglutarate
NAD(P)+ -> NAD(P)H
Oxidative deamination. |
|
|
Term
| 1st reaction of the Urea Cycle? |
|
Definition
| NH4+ (From Glu DH) + CO2 + 2ATP -> Carbamoyl Phosphate by Carbamoyl Phosphate Synthetase (CPSI) |
|
|
Term
| Where does the 1st step of the urea cycle occur? |
|
Definition
|
|
Term
| Which reactions of the urea cycle take place in the MT? |
|
Definition
1. Carbamoyl phosphate synthesis (enzyme- Carabomyl Phosphate Synthesis, CPS 1)
2. Citrulline synthesis
(enzyme- Orthine transcarbamoylase) |
|
|
Term
| What is the rate limiting step of Urea Cycle? |
|
Definition
| 1. Carbamoyl phosphate synthesis (enzyme- Carabomyl Phosphate Synthesis, CPS 1) |
|
|
Term
| Cytoplasmic reactions of the Urea Cycle? |
|
Definition
3. Arginosuccinate formed
4. Arginine formed
5. Ornithine and urea formed |
|
|
Term
| The _____ formed in the 5th reaction, in addition to urea, and is fed back into the MT from the cytosol. |
|
Definition
|
|
Term
| 1st reaction of the Urea Cycle: _____ |
|
Definition
CO2 + NH4+ + 2ATP -> 2ADP + Pi + Carbamoyl Phosphate
MT |
|
|
Term
| 2nd reaction of the Urea Cycle: ______ |
|
Definition
Ornithine + Carbamoyl Phosphate (From 1st reaction) -> Pi + Citrulline (Fed into Cytoplasm)
MT |
|
|
Term
| What is the source of ammonia for carbamoyl synthetase I? |
|
Definition
| Glutamate thru GDH reactions |
|
|
Term
| What is carbamoyl synthetase II? |
|
Definition
| an enzyme that catalyzes the reactions that produce carbamoyl phosphate in the cytosol. Used in pyrimidine synthesis |
|
|
Term
| What reaction is catalyzed by ornithine transcarbamoylase? |
|
Definition
2nd of the Urea Cycle
Ornithine + Carbamoyl phosphate -> Citrulline + Pi |
|
|
Term
| Where does the reaction catalyzed by ornithine transcarbamoylase occur? |
|
Definition
|
|
Term
| Where does citrulline react with aspartate and what enzyme catalyzes this reaction? |
|
Definition
Cytoplasm
Arginosuccinate synthetase |
|
|
Term
| Arginosuccinate synthetase reaction? |
|
Definition
Citrulline + aspartate + ATP -> argininosuccinate + AMP + 2 Pi
3rd reaction |
|
|
Term
| Which are the energy requiring steps in the urea cycle? |
|
Definition
1st- Carbamoyl Phosphate synthesis by CPS-I
3rd reaction argininosuccinate syntehsis |
|
|
Term
| 4 ATP is used in synthesis of 1 urea molecule |
|
Definition
2 ATP -> 2 ADP (1st reaction)
1 ATP -> 1 AMP, takes two ATP to get AMP back to ATP, so really 2 ATP (3rd Reaction) |
|
|
Term
| What enzyme cleaves argininosuccinic acid and what are the products of the reaction? |
|
Definition
Argininosuccinate lyase
fumarate and arginine. |
|
|
Term
| Which product of the Urea Cycle is a TCA intermediate and at what step does it occur? |
|
Definition
Fumarate
4th by Argininosuccinate lyase
Argininosuccinate -> Fumarate + Arginine |
|
|
Term
| Where does the Argininosuccinate lyase catalyzed reaction occur? |
|
Definition
|
|
Term
| Which enzyme releases urea from arginine and what are the products of the reaction? |
|
Definition
Arginase
Products are urea and ornithine |
|
|
Term
| Arginase reaction occurs where? |
|
Definition
|
|
Term
| Short-term regulation of the urea cycle is accomplished after a high protein meal that leads to high production of _______. _____ is also found in higher concentrations ______, which upregulates _____ enzyme. |
|
Definition
ammonia
N-acetylglutamate
Carbamoyl Phosphate Synthase I (1st step) |
|
|
Term
| N-acetylglutamate is a positive effector of ________ not _______. |
|
Definition
| positive effector for CPS I, MT (CPS II – cytoplasmic – not affected) |
|
|
Term
| Long-term regulation of the Urea Cycle occurs through ____ activation of urea cycle enzymes. |
|
Definition
|
|
Term
| For Long-term regulations of the Urea Cycle occurs during starvation by Elevated ____ levels causin increased expression of urea cycle enzymes, which comes from the metabolism of muscle _____ during prolonged starvation. |
|
Definition
|
|
Term
| Under extreme starvation, are urea cycle enzyme concentrations increased or decreased? Why? |
|
Definition
| Increase because of breakdown of proteins |
|
|
Term
| How is the mitochondrial form of carbamoyl synthetase regulated? |
|
Definition
| N-acetylglutamate activates it (positive effector) |
|
|
Term
| How is N-acetylglutamate synthesized? |
|
Definition
| from glutamate and acetyl-CoA. |
|
|
Term
| Hyperammonemia is more severe with deficiency at _____ or ______. |
|
Definition
CPS-I (reaction 1)
ornithine transcarbamoylase (reaction 2) |
|
|
Term
| With Hyperammonemia the metabolite prior to block are ____ in blood, e.g. ______. |
|
Definition
elevated
argininosuccinic aciduria |
|
|
Term
| Hyperammonemia can cause ____, which is characterized by neurological symptoms. |
|
Definition
|
|
Term
| With Hyperammonemia with secondary orotic aciduria, _______ is deficient. |
|
Definition
| Ornithine transcarbamoylase deficiency |
|
|
Term
| In Hyperammonemia with secondary orotic aciduria excess _______ leaks into the ______ and pushes _____ pathway |
|
Definition
Carbamoyl phosphate
cytoplasm
pyrimidine pathway |
|
|
Term
| Hyperammonemia with secondary orotic aciduria, Orotic acid excess not converted to _____. |
|
Definition
|
|
Term
| What small molecule with an alkaline pK accumulates when the urea cycle is genetically impaired? |
|
Definition
|
|
Term
| How does protein restriction help with the accumulation of ammonina when the urea cycle is genetically impaired? |
|
Definition
| Reduces the release of ammonia from amino acids by bacterial ureases |
|
|
Term
| amino acid component of hippuric acid? |
|
Definition
|
|
Term
| Orotic Acid is formed by ring closure from ______. |
|
Definition
|
|
Term
| Hyperammonemia is treated with Conjugation with ______ & _____; excreted in urine |
|
Definition
| benzoic acid and phenylacetic acid |
|
|
Term
|
Definition
| Benzoate + Glycine -> Hippuric acid |
|
|
Term
| benzoic acid becomes conjugated with _____ to form _____ so it can be eliminated through the urine. |
|
Definition
|
|
Term
| phenylacetate becomes conjugated with _____ to form _____ so it can be eliminated through the urine. |
|
Definition
glutamine
phenylacetylglutamine |
|
|
Term
| Why would you administer benzoic acid or phenylacetate to a patient? |
|
Definition
| They become conjugated with glycine and glutamine, and conjugation products (hippurate and phenylacetylglutamine) are excreted in the urine. Used for disposal of unwanted organic acids from dietary sources. |
|
|
Term
| How old is a patient likely that you administer benzoic acid or phenylacetate to? |
|
Definition
| Patient is likely to be a newborn if enzyme deficiency and adult if it’s cirrhosis. |
|
|
Term
| What amino acid is joined to benzoic acid to produce hippuric acid? |
|
Definition
|
|
Term
| What happens to hippuric acid? |
|
Definition
|
|
Term
| List the amino acids that are converted to pyruvate: _______ |
|
Definition
- Alanine
- Glycine
- Cysteine
- Serine
- Threonine
- Tryptophan |
|
|
Term
| synthesis of glutamine: _____ |
|
Definition
Glutamate + NH3 + ATP -> ADP + Glutamine
glutamine synthase |
|
|
Term
| degradation of glutamine: _____ |
|
Definition
Glutamine -> NH3 + Glutamate
by glutaminase |
|
|
Term
| Synthesis of asapargine: ______ |
|
Definition
| aspartate + NH3 + ATP -> Asparagine |
|
|
Term
| Glutamate can be made via transamination of _______. |
|
Definition
|
|
Term
| Glutamate can be made from glutamine via _____. |
|
Definition
|
|
Term
| asparaginase reaction: _____ |
|
Definition
| Asparagine + H2O -> Aspartate + NH3 |
|
|
Term
| What type of metabolites are produced during branched-chain amino acid (BCAA) degradation? |
|
Definition
|
|
Term
| In BCAA Degradation, BCAAs are ______ to _______ |
|
Definition
transaminated
branched-chain α-keto acids (BCKA) |
|
|
Term
| In BCAA Degradation, BCAAs are transaminated to BCKAs, which are converted to _____ by multienzyme complexes similar to ______ & _____ complexes. |
|
Definition
CoA thioesters
pyruvate and α-ketoglutarate DH complexes |
|
|
Term
| The BCAA Valine and isoleucine are converted into _______ CoA thioesters through BCAA Degradation, which are glucogenic or ketogenic? |
|
Definition
| succinyl CoA (glucogenic) |
|
|
Term
| The BCAA Leucine is converted into _______ CoA thioesters through BCAA Degradation, which are glucogenic or ketogenic? |
|
Definition
| acetoacetyl CoA (ketogenic) |
|
|
Term
| In Maple syrup urine disease there is an enzyme deficiency of _______. |
|
Definition
| BCKA dehydrogenase complexes (used in the Degradation of BCCA, in the step BCKA to thiol CoA esters) |
|
|
Term
| In Maple syrup urine disease, _____ products give diapers a “burnt-sugar, maple syrup” odor |
|
Definition
|
|
Term
| Maple syrup urine disease is characterized by _____ symptoms and is precipitated by ____ & ______ |
|
Definition
neurological
fever infection |
|
|
Term
| BCKA are an additional source of ______. |
|
Definition
|
|
Term
| BCKA -> ______ -> Propionyl CoA |
|
Definition
|
|
Term
| methylmalonic acidemia is a ______ disease |
|
Definition
| Branched chain amino acid |
|
|
Term
| propionyl-CoA feeds into _____ pathway; spills into urine with either ____ deficiency or enzyme deficiency so it is not converted into ______ |
|
Definition
methylmalonic pathway (Off Odd Chain Beta Oxidation)
cobalamin (Vitamin B12)
succinyl-CoA (typical end product) |
|
|
Term
| Amino Acid Degradation, all roads lead to _____ |
|
Definition
|
|
Term
| glutamine, proline, arginine, and histidine enter the TCA cycle through _______, which is then converted into _____. |
|
Definition
|
|
Term
| Conversion of _____ to ____ can be used to test for folate deficiency |
|
Definition
|
|
Term
| Overall reaction for the conversion of histidine to glutamate test for folate deficiency? |
|
Definition
Histidine -> FIGLU
FIGLU -> Glutamate requires THF (Folate) |
|
|
Term
| The conversion of FIGLU to Glutamate requires ______. |
|
Definition
|
|
Term
| Folate deficiency can be tested for with oral administration of ______, which produces _____ in urine when folate is deficient. |
|
Definition
|
|
Term
| amino acids that can be converted to acetyl-CoA: ______. |
|
Definition
|
|
Term
| Amino acids feed into the TCA primarily through _____. |
|
Definition
|
|
Term
| Amino acids entering the TCA cycle can serve as precursors for ______. |
|
Definition
|
|
Term
| Isoleucine & Leucine are converted to acetyl-CoA under which conditions? |
|
Definition
|
|
Term
| key reaction that allows amino acids to provide carbon skeletons for glucose synthesis? |
|
Definition
| Nitrogen disposal (ammonia to urea cycle) |
|
|
Term
| Nitrogen disposal (ammonia to urea cycle) provides carbon skeletons for glucose synthesis through ______. |
|
Definition
Fumarate
Argininosuccinate -> Fumarate + Arginine
Argininosuccinate Lyase |
|
|
Term
| homocysteine -> cystathionine by _______. |
|
Definition
|
|
Term
| S-Adenosylmethionine (SAM) metabolic function is? |
|
Definition
|
|
Term
| In the Methonine cycle S-Adenosylmethionine (SAM) eventually becomes? |
|
Definition
|
|
Term
| What molecule does ATP react with to yield SAM? |
|
Definition
|
|
Term
| What adenosyl containing molecule is produced when SAM donates its carbon? |
|
Definition
| S-adenosylhomocysteine (SAH) |
|
|
Term
| What are some of the molecules that require donations from SAM in their synthesis? |
|
Definition
"Methylated Products"
- Epinephrine
- Choline
- Creatine
- Nucleotides
- Melatonin |
|
|
Term
| How is homocysteine converted to methionine? |
|
Definition
- Vitamin B12 removes the methyl group methyltetrahydrofolate (methyl-THF) to produce tetrahydrofolate (THF)
- Methylated vitamin B12 (methyl-B12) transfers methyl group to homocysteine, producing methionine.
M-THF + B12 -> M-B12 + THF
Homocysteine + M-B12 -> methionine + B12 |
|
|
Term
| Homocystinuria is produced by a ______ enzyme deficiency |
|
Definition
| Cystathionine synthase deficiency |
|
|
Term
| Homocystinuria, in addition to Cystathionine synthase deficiency can be produced by ______ or _____ deficiencies. |
|
Definition
Folate and/or cobalamin (B12) deficiency
used in the metyhlation of homocysteine back into methonine |
|
|
Term
| If homocysteine builds up it is passed out of the methonine pathway and eventually converted into ____, which then goes onto the ______. |
|
Definition
|
|
Term
| Folate polyglutamylation results when folate is _____ in the cell by ______. |
|
Definition
trapped
polyglutamate tail (active form) |
|
|
Term
| ______ (_____ analog, cancer drug) also can also be polyglutamated |
|
Definition
|
|
Term
| With Methyl trap in ____ deficiency, _____ cannot convert to other forms & and all of the folate can be tied up as ______. |
|
Definition
B12
Methyl folate
methyl folate |
|
|
Term
| alkaptonuria is produced by a Deficiency for _______. |
|
Definition
|
|
Term
| Because of the homogentisate oxidase deficiency in alkaptonuria, ______ accumulates and is ____ to black product making the urine black. |
|
Definition
|
|
Term
| In addition to depositing in the urine, Homogentisate also deposits in the _______, known as _______. |
|
Definition
| deposits in cartilage (ochronosis) |
|
|
Term
| Homogentisate deposits in cartilage (ochronosis) affects ____, resulting in ______ by 30 and _____ by 50. |
|
Definition
vertebral column
back pain by age 30
joint replacements by age 50 |
|
|
Term
| Alkaptonuria results in an inability to breakdown Homogentisate, which is formed from the eventual breakdown of ______ into _____, which is eventually converted into Homogentisate. |
|
Definition
|
|
Term
| In PKU, there is a deficiency of _______, which forms _____ from _____. |
|
Definition
phenylalanine hydroxylase
Tyrosine from Phenylalanine |
|
|
Term
| In PKU patients tyrosine cannot be formed and therefore ______ cannot be formed from it. |
|
Definition
|
|
Term
| DOPA is made into ______ or _____. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| phenylalanine hydroxylase catalyzes what reaction? |
|
Definition
| Phenylalanine -> Tyrosine |
|
|
Term
| What cofactor is required by phenylalanine hydroxylase? |
|
Definition
| Tetrahydrobiopterin (BH4). |
|
|
Term
| Which minor metabolites of phenylalanine build up in PKU? |
|
Definition
| Phenylpyruvate, phenyllactate, phenylacetate |
|
|
Term
| Why do Phenylpyruvate, phenyllactate, phenylacetate build up in PKU? |
|
Definition
| Because phenylalanine is usually converted into tyrsoine, but with the phenylalanine hydroxylase deficiency, the phenylalanine instead is converted into the listed metabolites |
|
|
Term
| What damage is caused in PKU? and causes what? |
|
Definition
| Neurotoxic, causes mental retardation |
|
|
Term
| _____ is an essential amino acid for PKU patients. |
|
Definition
|
|
Term
| With PKU, the altered metabolites are neurotoxic up to age ___ |
|
Definition
|
|
Term
|
Definition
|
|
Term
| “Secondary” form of PKU results from a ______ block |
|
Definition
| Dihydrobiopterin reductase block |
|
|
Term
| Dihydrobiopterin reductase does what? |
|
Definition
BH2-> BH4 (BH4 -> BH2 by phenylalanine hydroxylase in the conversion of phenylalanine to tyrosine)
reduces dihydrobiopterin back to tetrahydrobiopterin, which is needed for Phe -> Tyr reaction (uses NADPH) |
|
|
Term
| What cofactor is required by phenylalanine hydroxylase? |
|
Definition
| Tetrahydrobiopterin (BH4) |
|
|
Term
| PKU 1 results from a ____ block. |
|
Definition
| phenylalanine hydroxylase block |
|
|
Term
| With PKU 1, Phenylalanine can’t be converted into ______. |
|
Definition
|
|
Term
| PKU _ cannot be treated by a low phenylalanine diet. |
|
Definition
|
|
Term
| Why do you still get neurological damage even on a low Phe diet with PKU2? |
|
Definition
| tetrahydrobiopterin (BH4) is also involved in formation and regeneration of neurotransmitters |
|
|
Term
| Tetrahydrobiopterin is needed for formation and regeneration of some ______. |
|
Definition
|
|
Term
| What is the amino acid precursor for serotonin and melatonin? |
|
Definition
|
|
Term
| Serotonin: produced in: ______ |
|
Definition
| brain, pineal gland, chromaffin cells in gut |
|
|
Term
| Melatonin is made from _______. |
|
Definition
|
|
Term
| Melatonin produced in: ______ |
|
Definition
|
|
Term
| Serotonin functions in _____ & ______. |
|
Definition
Peripheral Vasodilation
Neurotransmitter |
|
|
Term
| Carnitine synthesis pathway requires ____ & _____. |
|
Definition
| Pathway requires ascorbate and iron produces carnitine |
|
|
Term
| Deficiencies in carnitine production produce _______ symptoms |
|
Definition
| myopathic (muscle only) or systemic symptoms |
|
|
Term
| Which amino acid is the precursor for carnitine synthesis? |
|
Definition
|
|
Term
| Niacin is synthesized from ______. |
|
Definition
|
|
Term
| Niacin is synthesized from tryptophan, from part of a _____ pathway. |
|
Definition
|
|
Term
| Is the synthesis of Niacin from tryptophan sufficient? |
|
Definition
|
|
Term
| Cystinuria is a result of impaired reabsorption of ______ in the _____ & _____. |
|
Definition
dibasic amino acids (Lys, arg, ornithine, cystine (remember: 2 cysteines with disulfide bond, cys-S-S-cys)
kidneys and intestinal lumen |
|
|
Term
| Patients with Cystinuria can develop Kidney stones from the _____. |
|
Definition
| cystine (2 cysteines with disulfide bond, cys-S-S-cys) |
|
|
Term
| The impaired reabsorption of Cystinuria is caused by a defective _______. |
|
Definition
|
|
Term
| Hartnup disease is caused by Defective intestinal absorption of _____ & _____ |
|
Definition
|
|
Term
| Patients with Hartnup disease present with ____ symptoms. |
|
Definition
| Pellegra symptoms (fand neurological) |
|
|
Term
| What are the precursors for synthesis of creatine? |
|
Definition
|
|
Term
| creatine phosphate provides a store of a ______. |
|
Definition
| high-energy phosphate bonds |
|
|
Term
| In resting muscle, most creatine is present as ______ (ATP/ADP starts high). |
|
Definition
|
|
Term
| When muscle is used and ATP declines, creatine phosphate can create an instant energy source thru the reversible ______ reaction |
|
Definition
|
|
Term
| Creatine is not degraded ______. |
|
Definition
|
|
Term
| Creatine _____ spontaneously to ______ instead of being broken down by enzymatic degradation. |
|
Definition
|
|
Term
| creatinine is utilized in urinalysis as test of _____. |
|
Definition
| glomerular filtration rate (GFR) |
|
|
Term
| Overall reaction and precursors for Melanin: ______ |
|
Definition
| Phenylalanine -> Tyrosine -> DOPA -> melanin |
|
|
Term
| DOPA is converted into Melanin by the enzyme? |
|
Definition
|
|
Term
| Melanin functions as a ______ |
|
Definition
|
|
Term
| ____ absorbs UV light; aromatic rings |
|
Definition
|
|
Term
| Melanin is polymerized _____ (from _____); potent UV screen |
|
Definition
|
|
Term
| melanin is located where? |
|
Definition
| distal to nucleus, sunny side |
|
|
Term
| Overall reaction and precursors for Melatonin: _______ |
|
Definition
| Tryptophan -> 5-hydroxy tryptophan -> serotonin -> melatonin |
|
|
Term
|
Definition
|
|
Term
| location of melanin synthesis |
|
Definition
skin, hair, iris, and retinal pigment epithelium
distal to nucleus (sunny side) |
|
|
Term
| phosphoglycerides (aka glycerophospholipids) are like triglyceride, but instead of 3rd fatty acid, you have a _____ group. |
|
Definition
|
|
Term
| What is the name and structure of the core phospholipid from which all the others are derived? |
|
Definition
|
|
Term
Why are phospholipids amphipathic?
- Hydrophobic tails: _____ tails
- Hydrophilic head: ____ head group |
|
Definition
|
|
Term
| Which phospholipid has a role in intracellular signaling? |
|
Definition
|
|
Term
| What structural feature distinguishes plasmalogens from the other phospholipids? |
|
Definition
| Unsaturated fatty acid at carbon 1. Ether linkage at carbon 1 (vs. ester) |
|
|
Term
| What fundamental structure is joined in a dimer to form cardiolipins? |
|
Definition
|
|
Term
| ______(de novo) pathway for the synthesis of phosphoglycerides |
|
Definition
|
|
Term
| Phosphatidic (de novo) pathway for the synthesis of phosphoglycerides involves the activation of ______. |
|
Definition
|
|
Term
| _____ is the major component of mitochondrial inner membrane. |
|
Definition
|
|
Term
| ______ is an intermediate in phosphoglyceride synthesis |
|
Definition
|
|
Term
| Two pathways for phosphoglyceride synthesis: _______ |
|
Definition
|
|
Term
| The phosphatidic (de novo) pathway involves the Synthesis of phosphatidic acid from _______ |
|
Definition
|
|
Term
| The phosphatidic (de novo) pathway involves the reaction of phosphatidic acid with ____ to form activated intermediate _____ |
|
Definition
CTP
CDP- DAG (CDP diacyl glycerol) |
|
|
Term
| Reaction of CDP- DAG to attach _____. |
|
Definition
|
|
Term
| Inositol synthesized from ______. |
|
Definition
|
|
Term
| In the salvage pathway we are activating ______ instead of the ______ in the |
|
Definition
| the group we are attaching instead of the intermediate (phosphatidic acid) as is done in the de novo pathway |
|
|
Term
| phosphatidic acid is an intermediate for which pathway(s)? |
|
Definition
|
|
Term
| phosphatidic acid is an intermediate in _____ synthesis |
|
Definition
|
|
Term
| phosphatidic acid can make either ____ or _____. |
|
Definition
| phosphoglyceride or triglyceride |
|
|
Term
| phosphatidic acid synthesized from _____ |
|
Definition
|
|
Term
| Outline the steps in the formation of phosphatidylinositol from CTP and phosphatidic acid. |
|
Definition
> Synthesis of phosphatidic acid from glycerol-3-phosphate
> Reaction of phosphatidic acid with CTP to form activated intermediate (CDP-diacylglycerol)
> Reaction of CDP-DAG to attach inositol (inositol synthesized from glucose 6P) |
|
|
Term
| Outline the steps in the formation of phosphatidylcholine from free choline and CTP. |
|
Definition
> Phosphatidate loses the Pi
> Choline is activated by phosphorylation (ATP -> ADP), then reacts with CTP to form CDP-choline (vs. phosphatidic acid being activated in de novo)
> DAG and CDP-choline joined to form lecithin |
|
|
Term
| How is choline activated in salavage pathway for phosphoglyceride synthesis? |
|
Definition
|
|
Term
| What type of linkage do CDP-diglyceride and CDP-choline share in common? |
|
Definition
|
|
Term
| In the Remodeling Of Phosphoglycerides, Phospholipases do what? |
|
Definition
|
|
Term
|
Definition
| cleaves fatty acid off C1 |
|
|
Term
|
Definition
| cleaves fatty acid off C2 |
|
|
Term
|
Definition
| cleaves off entire phospho group of C3 and R3 Group |
|
|
Term
|
Definition
| cleaves R3 group and O connecting P to R3 |
|
|
Term
| What type of fatty acid usually winds up on position 1? |
|
Definition
|
|
Term
| What type of fatty acid usually winds up on position 2? |
|
Definition
|
|
Term
| What is attached to the carbon at position 3? |
|
Definition
|
|
Term
| In the remodeling Of Phosphoglycerides, Acyltransferases do what? |
|
Definition
| replace the fatty acids (Phospholipases remove fatty acids) |
|
|
Term
| Tissues differ in ____ components |
|
Definition
|
|
Term
| Phosphatidyl _____ is remolded to form phosphatidyl choline |
|
Definition
|
|
Term
| In the remodeling of phosphatidyl serine to form phosphatidyl choline, the first step takes place in the liver ______, where phosphatidyl serine loses ______ to become the intermediate ______. |
|
Definition
|
|
Term
| For the second step of the emodeling of phosphatidyl serine to form phosphatidyl choline, it takes place in the liver _______, where phosphoethanolamine recieves three _____ groups from three _____ |
|
Definition
microsomes
methyl groups
3 SAMs |
|
|
Term
| Describe the steps in the remodeling of phosphatidyl serine to form phosphatidyl choline. |
|
Definition
- In liver mitochondria, CO2 leaves phosphatidylserine to become phosphoethanolamine
- In liver microsomes, 3 SAM donate 3 CH3 to phosphoethanolamine to make phosphatidylcholine |
|
|
Term
| _______ are major components of membrane in brain and muscle |
|
Definition
|
|
Term
|
Definition
| Platelet Activating Factor (PAF) |
|
|
Term
| What is the name of the methyl donor for the remodeling of phosphatidyl serine to form phosphatidyl choline? |
|
Definition
|
|
Term
| Platelet Activating Factor (PAF) And _______ Derived From Same Pathway |
|
Definition
|
|
Term
| What type of linkage joins the acyl group to position 1 for PAF and Ethanolamine Plasmalogen? |
|
Definition
|
|
Term
| What is the main difference between the acyl groups attached to position 2 for PAF and Ethanolamine Plasmalogen? |
|
Definition
| R group (fatty acid) on ethanolamine plasmalogen vs. CH3 on PAF |
|
|
Term
|
Definition
| vasodilation (can make you faint, lightheaded, platelet adhesion (blood clotting enhanced), chemotaxis (fighting infection) |
|
|
Term
| Ceramide is an example of a _____ |
|
Definition
|
|
Term
| Phosphatidic Acid is an example of a _____ |
|
Definition
|
|
Term
| Ceramide Is Like A _______ |
|
Definition
|
|
Term
| Ceramide is a sphingosine with a ____ side chain on the _C |
|
Definition
|
|
Term
| What substitutes for glycerol in sphingolipids? |
|
Definition
|
|
Term
|
Definition
| Derivative for a lot of different sphingolipids. Different things attach at C1. |
|
|
Term
| What type of lipid is sphingomyelin? |
|
Definition
|
|
Term
| What is a glycosphingolipid? |
|
Definition
| Carbohydrate attached to a ceramide |
|
|
Term
| Where are Carbohydrates added to the ceramide in glycosphingolipids? |
|
Definition
|
|
Term
| ___ substance gives rise to a and b substance. |
|
Definition
|
|
Term
| The sugars in H,A, and B substances are attached to a _______. |
|
Definition
|
|
Term
| The sugars in H,A, and B substances are an example of a _____ liped |
|
Definition
|
|
Term
| Formation of A substance: ______ |
|
Definition
| From H substance by GalNAc Transferase, which adds a GalNAc group using UDP-GalNAc as an activated carrier |
|
|
Term
| Formation of B substance: ______ |
|
Definition
| From H substance by Gal Transferase, which adds a Gal group using UDP-Gal as an activated carrier |
|
|
Term
| Blood Group O is Represented by ___ substance. |
|
Definition
|
|
Term
| Blood Group A is Represented by ___ substance. |
|
Definition
|
|
Term
| Blood Group B is Represented by ___ substance. |
|
Definition
|
|
Term
| Are there different genes for the enzymes that produce the blood types? |
|
Definition
| No just different alleles |
|
|
Term
|
Definition
| Alleles = variants of the same gene |
|
|
Term
| Can you be Hetero with O type? |
|
Definition
|
|
Term
| How do you get the type A or type B phenotype? |
|
Definition
|
|
Term
| Can you be hetero for type A or type B phenotype? |
|
Definition
|
|
Term
| A substance contains ______ sidebranch |
|
Definition
|
|
Term
| B substance contains ____ sidebranch |
|
Definition
|
|
Term
| Both A& B are derived from H substance, a ____. |
|
Definition
|
|
Term
| Most common types of Lysosomal Storage Diseases are _____ & ______. |
|
Definition
| Tay-Sachs and Gaucher Disease |
|
|
Term
| In Tay Sachs which enzyme is deficient? |
|
Definition
|
|
Term
| In Gaucher which enzyme is deficient? |
|
Definition
|
|
Term
| In Fabry which enzyme is deficient? |
|
Definition
|
|
Term
| In Krabbe which enzyme is deficient? |
|
Definition
|
|
Term
| In Metachromatic Leukodystrophy which enzyme is deficient? |
|
Definition
|
|
Term
| Lysosomal Storage Diseases, The Sphingolipidoses are resultant of inability to break down ______ |
|
Definition
| sphingolipids (examples we did are of glycosphingolipid) |
|
|
Term
| Two types of sphingolipids: _____ |
|
Definition
| Sphingomyelin & glycosphingolipid. |
|
|
Term
| How long is the side chain on cholesterol? |
|
Definition
|
|
Term
| 1st precursor in cholesterol synthesis? |
|
Definition
|
|
Term
| What modifications are made to the CPPP ring in cholesterol structure? |
|
Definition
- Hydroxyl group (on C3)
- 2 methyl groups (on C10 and C13)
- Branched hydrocarbon chain (on C17) |
|
|
Term
| How is the side chain on cholic acid different from that of cholesterol? |
|
Definition
| - Cholic acid side chain only has 5 carbons (Cholesterol has 8), one of which is a COO- group |
|
|
Term
| How is deoxycholic acid different from cholic acid? |
|
Definition
| Missing an OH group from C12 |
|
|
Term
| What makes the bile acids amphipathic? |
|
Definition
| The direction their side chains are pointing. |
|
|
Term
| Bile acids being amphipathic allows them to ______ |
|
Definition
| attach hydrophobic side to fat droplets and emulsify |
|
|
Term
| In cholesterol synthesis, Acetyl-CoA is converted into _____. |
|
Definition
|
|
Term
| In cholesterol synthesis, HMG-CoA is then _____ into _____ by _____ enzyme using ______ in the process. |
|
Definition
| reduced into Mevalonate by HMG-CoA Reductase using 2 NADPH in the process |
|
|
Term
| In cholesterol synthesis, Mevalonate is further reacted into _______ & its isomer ______. |
|
Definition
Isopentyl Pyrophosphate
Demethylallyl Pyrophosphate |
|
|
Term
| In cholesterol synthesis, Isopentyl Pyrophosphate an intermediate has a _____. |
|
Definition
|
|
Term
| Isopentyl Pyrophosphate & Demethylallyl Pyrophosphate are eventually converted to _____ |
|
Definition
|
|
Term
| Squallene is converted to ____ in cholesterol synthesis. |
|
Definition
|
|
Term
| _____ is converted into cholesterol |
|
Definition
|
|
Term
| HMG-CoA reductase uses _____ to reduce HMG-CoA into ______ |
|
Definition
|
|
Term
| What is the regulated and committed step of cholesterol synthesis? |
|
Definition
|
|
Term
| HMG-CoA reductase is regulated by _____ |
|
Definition
| Feedback inhibition by free cholesterol (non esterfied) |
|
|
Term
| HMG-CoA reductase is stimulated by ______ |
|
Definition
|
|
Term
| ____ is the basic ring structure of cholesterol and bile acids |
|
Definition
|
|
Term
| Does squalene have the intact CPPP (cyclopentanoperhydrophenanthrene) nucleus? |
|
Definition
|
|
Term
| How many carbons in squalene? |
|
Definition
|
|
Term
| Squalene -> _____ -> cholesterol |
|
Definition
|
|
Term
| HMG-CoA reductase uses _ NADPH |
|
Definition
|
|
Term
| HMG-CoA reductase is inhibited by? |
|
Definition
|
|
Term
| Give the site of action of cholesterol lowering drugs (e.g. the statins: lovastatin, mevastatin). |
|
Definition
| HMG-CoA reductase inhibitors |
|
|
Term
| Bile Acids are converted from? |
|
Definition
|
|
Term
| Primary bile acids come from where? |
|
Definition
|
|
Term
| Secondary bile acids come from where? |
|
Definition
| when exposed to intestinal flora, made by bacteria |
|
|
Term
| Secondary bile acids include: _____ |
|
Definition
deoxycholic acid
lithocholic acid |
|
|
Term
| deoxycholic acid is produced from? |
|
Definition
| Cholic acid (via intestinal bacteria) |
|
|
Term
| lithocholic acid is produced from? |
|
Definition
| Chenodeoxycholic acid (via intestinal bacteria) |
|
|
Term
| What are bile acids needed for? |
|
Definition
| Emulsifying fats, lipid absorption |
|
|
Term
| What are the two major bile acids produced from cholesterol? |
|
Definition
| Cholic and and chenodeoxycholic acid |
|
|
Term
| How does the quantity of bile acid production compare to other uses of cholesterol? |
|
Definition
|
|
Term
| What is the rate limiting step in the conversion of cholesterol into bile acids? |
|
Definition
| Cholesterol -> 7α-hydroxycholesterol via 7α-hydroxylase |
|
|
Term
| 7α-hydroxylase converts ____ into 7α-hydroxycholesterol using: ________. |
|
Definition
Cholesterol
O2 molecular oxygen, H+, and NADPH |
|
|
Term
| Bile acids ____ level of 7α-hydroxylase |
|
Definition
|
|
Term
| ____ & _____ induce α-hydroxylase synthesis |
|
Definition
| Cholesterol and thyroid hormones |
|
|
Term
| What is a conjugated bile acid? |
|
Definition
| Bile acids conjugated with glycine or taurine |
|
|
Term
| Conjuation of: Chenodeoxycholyl-CoA -> ____ or _____ |
|
Definition
| Glycochenodeoxycholic acid and taurochenodeoxycholic acid |
|
|
Term
| 7 α-hydroxylase is regulated by ______ |
|
Definition
| feedback inhibition by bile acids |
|
|
Term
| Synthesis of the secondary bile acids by _____. |
|
Definition
|
|
Term
| Conjuation of: Cholyl-CoA -> ____ or _____ |
|
Definition
| Glycocholic acid and taurocholic acid |
|
|
Term
| Pancreatic lipase gains access to _____ with the help of bile salts. |
|
Definition
|
|
Term
| _____ plus ____ are absorbed at the brush border of the mucosal cell in the intestines.(unstirred layer) |
|
Definition
|
|
Term
| Resynthesis of TG after their adsorption into the intestinal mucosal cell requires “activated” FFA in form of _____. |
|
Definition
|
|
Term
| * What happens to the Long-chain TG reformed in the intestinal mucosal cells? the short & medium? |
|
Definition
Long- Packaged into chylomicrons and dumped into the lymph and then into the blood
Short- and medium-chain FFA transported directly through portal to liver; attach to albumin
–NO!!!!!!!! resynthesis of short- and medium-chain TG |
|
|
Term
| ____-chain TGs circulate as chylomicrons or VLDL |
|
Definition
|
|
Term
| ______ releases FFA from chylomicrons or VLDL for uptake by adipose tissue |
|
Definition
|
|
Term
| Free glycerol trapped by ____ in liver |
|
Definition
|
|
Term
| TG synthesis: _____ + 3 Fatty Acyl CoAs |
|
Definition
|
|
Term
| Where does the G3P for TG synthesis come from in the adipose? |
|
Definition
|
|
Term
| Where does the G3P for TG synthesis come from in the liver? |
|
Definition
DHAP (Glycolysis)
or
Glycerol -> G3P by glyerol Kinase |
|
|
Term
| FFA are activated for TG synthesis in the adipose and liver by ______ enzymes like in the intestinal lumen |
|
Definition
|
|
Term
| ______ synthesis in both the liver and adipose supports esterification to TGs |
|
Definition
|
|
Term
| FFA are transported on _____ upon release from the adipose tissue, and the glycerol is transported to the _____. |
|
Definition
|
|
Term
| _____ Regulation Of Glycerol 3P Synthesis and its future involvement in TG synthesis. |
|
Definition
|
|
Term
| Malonyl-CoA is formed how for TG syntheis? |
|
Definition
Acetyl CoA + ATP + CO2 -> ADP + Malonyl CoA
Enzyme-> Acetyl CoA Carboxylase |
|
|
Term
| Acetyl CoA Carboxylase is active in phosphorylated or dephosphoryalted form? |
|
Definition
|
|
Term
| What dephosphorylates Acetyl-CoA Carboxylase |
|
Definition
|
|
Term
| PP2A allosteric effectors |
|
Definition
- glucagon, epinhephrine
+ insulin |
|
|
Term
| Kinase that phosphorylates Acetyl-CoA Carboxylase, allosteric regulations |
|
Definition
| + AMP (low energy, don't need to synthesize TG) |
|
|
Term
| Acetyl-CoA Carboxylase is allosterically regulated by? |
|
Definition
|
|
Term
| What key fat synthesis enzymes are stimulated by insulin? |
|
Definition
| PP2A (protein phosphatase 2A), which dephosphorylates and activates Acetyl-CoA carboxylase (forms malonyl CoA from Acetyl CoA) |
|
|
Term
| Fatty Acid Synthase Complex; Multienzyme complex; ____ polypeptide |
|
Definition
|
|
Term
| Acyl carrier protein (ACP) of the Fatty Acid Synthase Complex contains ______. |
|
Definition
|
|
Term
| FA synthesis occurs in Polymerization of ___ units |
|
Definition
|
|
Term
| Elongation cycle of FA synthesis reverses steps in ______. |
|
Definition
|
|
Term
| Elongation cycle of FA synthesis uses _____ to reduce. |
|
Definition
|
|
Term
| ____ is a signal that the TCA is full. |
|
Definition
|
|
Term
| When TCA is full, ____ is transported to the cytoplasm to deliver Acetyl CoA for FA synthesis. |
|
Definition
| Citrate -> OAA + Acetyl CoA |
|
|
Term
| Desaturases can’t insert beyond _____ |
|
Definition
|
|
Term
| Blood sample from apoE deficiency would produce both a _____ form the _____ solution and a ____ layer at the top from the ______. |
|
Definition
cloudy (VLDL and remnants build up)
fatty (chylomicrons build up) |
|
|
Term
| B-100 contains ____-receptor binding domain, so that _____ can be endcytosed and deliver cholesterol to _______. |
|
Definition
|
|
Term
| **5.6 Which receptor binds Apo E? |
|
Definition
| lipoprotein receptors including LDL receptor & chylomicron receptors on the Liver Cell |
|
|
Term
| Three way regulation of cholesterol levels in the liver: ________ ***** |
|
Definition
1. down regulation of receptors, apoE (gene regulation)
2. inhibition of HMG-CoA reductase (Enzyme in formation of cholesterol)
3. stimulation of ACAT:
Cholesterol + Acyl-CoA -> Cholesterol Ester + CoA-SH |
|
|
Term
| Cholesterol esters are given from HDL to ______ |
|
Definition
|
|
Term
| 10.3 What kind of interchange occurs between HDL particles and VLDL and chylomicron particles? Give cholesterol esters alone or in exchange for triglycerides. Also gives them lipoproteins (apoC and apoE). |
|
Definition
|
|
Term
| HDL do not contain ____ apo |
|
Definition
|
|
Term
| Nascent HDL starts of with ______ |
|
Definition
| apo A-I Phospholipids and Cholesterol |
|
|
Term
| What does ApoAI allow HDL to do? |
|
Definition
| Bind to periph tissue to uptake Cholesterol |
|
|
Term
| HDL binds to the Liver and _____ hrydrolyzes off ______ of HDL and into the liver. |
|
Definition
Hepatic Lipase
Cholesterol Esters |
|
|
Term
| Where do nascent HDLs come from? |
|
Definition
|
|
