Term
|
Definition
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Term
| PFK-1 (stands for and function) |
|
Definition
Phosphofructokinase-1
Phosphorylates Fructose 6-P
to
Fructose 1,6-bis-P |
|
|
Term
| Draw the chemical structures of glyceraldehyde 3-phosphate and 1,3-bisphosphoglycerate (22.5 p. 405) |
|
Definition
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|
Term
|
Definition
|
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Term
| What are the three pyruvate enzymes we've learned thus far, and what does each one do? |
|
Definition
Pyruvate Dehydrogenase- Oxidizes pyruvate and adds it to CoA
Pyruvate Carboxylase- Adds a carboxyl group to pyruvate, converting it to oxaloacetate
Pyruvate Kinase- donates a high energy phosphate to ADP and converts phosphoenol-pyruvate to pyruvate |
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Term
| What are the three steps that are irreversible in glycolysis, and their corresponding enzymes? |
|
Definition
D-glucose to Glucose 6-P via hexokinase (or glucokinase in liver)
Fructose 6-P to Fructose 1,6-bis-P via phosphofructosekinase
phosphoenolpyruvate to pyruvate via pyruvate kinase |
|
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Term
| Draw dihydroxyacetone-P (DHAP) |
|
Definition
|
|
Term
|
Definition
Aspartate Transaminase
Turns OAA to Aspartate pg. 574 |
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Term
Name of enzyme that makes new branches (1-6 linkages) on Glycogen
&
Name of enzyme that breaks down branches (1-6 linkages) on Glycogen |
|
Definition
Branching Enzyme
Debrancher Enzyme |
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Term
| What enzyme catalyzes a rxn to make glycogen bigger using UDP-G? |
|
Definition
|
|
Term
| How does branching enzyme work? |
|
Definition
| By transferring a link from 1-4 to 1-6 |
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Term
| What does UDP-G stand for? |
|
Definition
| Uridine Diphosphate Glucose |
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|
Term
Draw a schematic for UTP
Be able to explain why this is a nucleotide |
|
Definition
| It is a nucleotide because it has a nitrogenous base of uracil, a pentose sugar of ribose, which make uridine, and phosphate(s) attached to the pentose ring |
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Term
| What is the structure of pyrophosphate? |
|
Definition
Two inorganic phosphates bonded to eachother
PPi |
|
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Term
| What molecule actually donates a glucose ring to glycogen? |
|
Definition
| Uridine Diphosphate Glucose (UDP-G) |
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Term
|
Definition
|
|
Term
| General rule regarding phosphorylation activation or deactivation |
|
Definition
Fasting state enzymes are generally activated by phosphorylation
Fed state enzymes are generally deactivated by phosphorylation |
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Term
|
Definition
| Phosphatidylinositol bisphosphate |
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Term
| Hexokinase and glucokinase |
|
Definition
Enzymes responsible for the first rxn in glycolysis
Hexokinase turns glucose to glucose 6-p in muscle cells
Glucokinase does the same in liver cells |
|
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Term
|
Definition
DHAP turns into glycerol 3-p shuttle. This goes into the ETC complex II with FAD(2H), gives away e- pair, and comes back with NAD+.
Mitochondrial glycerol 3-P dehydrogenase turns glycerol 3-P shuttle back to DHAP |
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Term
| Glyceraldehyde 3-P dehydrogenase: what reaction does this catalyze? |
|
Definition
Glyceraldehyde 3-p ---Pi goes in---NAD+ to NADH---->1,3-bis-phosphoglycerate
1,3-bis-phosphoglycerate |
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Term
|
Definition
|
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Term
|
Definition
| OAA gets turned to Aspartate in matrix, Aspartate leaves matrix to cytosol and turns back to OAA. OAA retrieves NADH, turn to Malate which goes into matrix and gives e- to ETC. Malate then gets turned back to OAA. |
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Term
| Draw: Dihydroxyacetone phosphate (DHAP) |
|
Definition
CH2OPO3(2-)
C=O
CH2OH
(Ketose) |
|
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Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Draw the Biosynthetic functions of glycolysis diagram: |
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Definition
|
|
Term
| Regulation of Hexokinase (or Glucokinase) |
|
Definition
| Increased amounts of glucose 6-P inhibit these enzymes |
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Term
| Regulation of phosphofructokinase-1: |
|
Definition
AMP, fructose 2,6-bis-p Activates
ATP, citrate inhibit |
|
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Term
| Regulation of Pyruvate Kinase |
|
Definition
Fructose 1,6-bis-P Activates
ATP, alanine, and glucagon inhibit |
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Term
|
Definition
| First reaction of gluconeogenesis: turns pyruvate into OAA |
|
|
Term
| Phosphoenolpyruvate carboxykinase (PEPCK) rxn |
|
Definition
Gluconeogenesis:
OAA --- GTP to GDP---> PEP |
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Term
| Fructose bis-phosphatase function |
|
Definition
Control step in gluconeogenesis:
Fructose 1,6-phosphate ---hydrolysis rxn---Pi comes out---->fructose 6-P |
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Term
| Glucose 6-phosphatase rxn |
|
Definition
Control step in gluconeogenesis:
Glucose 6-P ----hydrolysis rxn---Pi comes out---> GLUCOSE! |
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Term
| 3 control steps of Gluconeogenesis: |
|
Definition
| PEP carboxykinase, fructose bis-phosphatase, glucose 6-phosphatase |
|
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Term
| OAA disguises: why they are needed and what they are. |
|
Definition
OAA needs a way to leave the mitochondrial matrix, so needs a disguise.
Turns into Malate via malate dehydrogenase. Turns back into OAA via Malate dehydrogenase in cytosol.
OAA can turn into Aspartate to accomplish this same task. |
|
|
Term
NET glycolysis rxn (9)
How many ATPs does glycolysis make?
How many ATPs does glycolysis net make? |
|
Definition
Glucose + 2 NAD+ + 2Pi + 2 ADP --> 2 pyruvate 2 NADH + 4H+ + 2 ATP + 2 H2O
glycolysis makes 4 ATP but uses 2 so the net ATP produced is 2. |
|
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Term
| Where does glycolysis occur? |
|
Definition
|
|
Term
| What does AMP do in muscle cells but not liver cells? |
|
Definition
| Acts as an allosteric activator for glycogen phosphorylase. |
|
|
Term
| What two things work to completely activate muscle glycogen phosphorylase? |
|
Definition
|
|
Term
| Give the reactions catalyzed by myosin ATPase and adenylate kinase |
|
Definition
myosin ATPase breaks down ATP to ADP
Adenylate Kinase Takes two ADPs and makes one an ATP and the other an AMP |
|
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Term
| net gluconeogenesis rxn (9) |
|
Definition
2 pyruvate ---- glucose
4 ATP ---- 4 ADP
2 GTP ---- 2 GDP
2 NADH ---- 2 NAD+
---- 6 Pi |
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Term
| Malate dehydrogenase function |
|
Definition
Oxaloacetate to malate (reversible)
This can happen in matrix and in cytosol, so OAA can disguise itself as Malate. |
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|
Term
|
Definition
|
|
Term
Transaminations: Generalize
Aspartate transaminase: What does it do? |
|
Definition
To transfer an amino group.
Aspartate transaminase
OAA reacts with glutamate (an alpha amino acid) and turns it into alpha-ketoglutarate (an a-keto acid). This turns OAA to Aspartate. |
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|
Term
| Carboxylases: what vitamin acts as a catalytic cofactor? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Three most important noncarbohydrate precursors for liver synthesis of glucose: |
|
Definition
Alanine: becomes pyruvate
Lactate: becomes pyruvate
Glycerol: becomes glycerol 3-p, then turns to DHAP.
(Other amino acids: turn to pyruvate) |
|
|
Term
|
Definition
Alanine reacts with a-ketoglutarate, a-KG turns to glutamate, and Alanine turns to pyruvate.
Alanine is the a-amino of pyruvate |
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Term
| Glycerol Kinase and Glycerol 3-P dehydrogenase |
|
Definition
| This turns glycerol into glycerol 3-P. This is so glycerol can eventually become DHAP via glycerol 3-p dehydrogenase. |
|
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Term
| Draw: glycerol 3-Phosphate |
|
Definition
|
|
Term
| Name the enzymes for glycolysis and glycogenolysis that are simultaneously activated by a rising AMP level in a muscle cell |
|
Definition
Glycogen phosphorylase (phosphorylase b to phosphorylase a)
Phosphofructokinase-1 (PFK-1) |
|
|
Term
| What allows more glycogen to be stored per gram in the liver than in muscle? (part of muscle glycogen synthesis regulation) |
|
Definition
| Glycogen is a stronger feedback inhibitor of muscle glycogen synthase than of liver glycogen synthase |
|
|
Term
| Why does the level of AMP increase so much during exercise? |
|
Definition
| Both adenylate kinase (ADP + ADP --> ATP + AMP) and cAMP phosphodiesterase are creating AMP |
|
|
Term
| Describe the regulation of glycogen degradation in skeletal muscle (3) |
|
Definition
| Related to the availablility of ATP, the highest demands for which occur during anaerobic glycolysis; Calcium is released from the sarcoplasmic reticulum (and not just epinephrine as in liver cells) which activates Ca2+-calmodulin, AMP that is created by adenylate kinase increases the glycolysis rate |
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|
Term
| Draw a schematic for phosphatidylinositol bisphosphate (PIP2) |
|
Definition
-
Use Google Images :D No images in book or provided unless drawn in class (use class note drawings if possible). |
|
|
Term
| Draw a schematic for a Diacyl glyceride (DAG) |
|
Definition
C-Fatty Acid
C-Fatty Acid
CH-OH |
|
|
Term
| Draw a shematic for inositol triphosphate (IP3) |
|
Definition
| Draw a rectangle, with inositol in it, and three -P groups attached to it |
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|
Term
| Describe the signal transduction when epinephrine binds to a β-adrenergic receptor (a heptahelical receptor) (6) |
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Definition
| same as a glucagon signal transduction; G-protein gets GTP (picks up a GTP which then activates it) which moves to activate adenylate cyclase, making cAMP, activating PKA, which both phosphorylates/activates phosphorylase kinase and phosphyrlates/inactivates glycogen synthase, phosphorylase kinase phosphorylates/activates glycogen phosphorylase which begins glycogenolysis |
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|
Term
| Describe the signal transduction when epinephrine binds to an a-adrenergic receptor (11) |
|
Definition
| only in liver cells; G-proteins transfer the signal to the membrane-bound phospholipase C, which then hydrolyzes phosphatidylinositol bisphosphate (PIP2) to form diacylglycerol (DAG) and inositol triphosphate (IP3), IP3 stimulates the release of Ca2+ from the endoplasmic reticulum, DAG and Ca2+ both then activate protein kinase C, which then inactivates/phosphorylates glycogen synthase, Ca2+ also activates Ca2+-calmodulin which then activates both calmodulin dependent protein kinase (which phosphorylates/inactivates glycogen synthase) and phosphorylase kinase which both activates/phosphorylates glycogen phosphorylase and inactivates/phosphorylates glycogen synthase |
|
|
Term
| Three roles of protein phosphatase-1 (PP-1) |
|
Definition
activates glycogen synthase
deactivates glycogen phosphorylase
deactivates phosphorylase kinase |
|
|
Term
| What allows for the fine-tuning of glycogen synthase? |
|
Definition
| That it can be partly inactivated by phosphorylation, and can be phosphorylated many times to different levels of inactivation |
|
|
Term
| Describe the signal transduction when glucagon binds to a a heptahelical receptor (6) |
|
Definition
| same as β-adrenergic signal transduction; G-protein gets GTP which moves to activate adenylate cyclase, making cAMP, activating PKA, which both phosphorylates/activates phosphorylase kinase and phosphyrlates/inactivates glycogen synthase, which phosphorylates/activates glycogen phosphorylase which begins glycogenolysis |
|
|
Term
|
Definition
Pyruvate -----NADH to NAD+-----> Lactate
Enzyme that catalyzes this reaction is lactate dehydrogenase |
|
|
Term
| Why is gluconeogenesis dependent on B-oxidation? |
|
Definition
Fatty acids are used in liver for energy for gluconeogenesis.
Glycerol is used for DHAP synthesis.
NADH is used for disguising OAA into Malate. |
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|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Describe the regulation of liver glycogen metabolism by insulin (5) |
|
Definition
| Glucose stimulates insulin release and suppresses glucagon release, activation of hepatic protein phosphotase 1 (PP-1) through the insulin receptor tyrosine kinase which leads to a dephosphorylation cascade, cAMP levels decrease and PKA reassociates with its inhibitory subunits and becomes inactive, glycogen phosphorylase a and glycogen synthase are dephosphorylated, activating glycogen synthase and inactivating glycogen phosphorylase. |
|
|
Term
|
Definition
|
|
Term
| Effect of Calcium on Glycogenolysis |
|
Definition
|
|
Term
| Draw a schematic for UDP-G |
|
Definition
Uridine-P-P-Glucose
Uracil
(N glycosidic linkage to ribose)
Ribose-P-P-Glucose |
|
|
Term
| What kind of lysing occurs when glycogen is broken down? |
|
Definition
Phosphorylation
Glucose --> Glucose 6-P
NOT HYDROLYSIS! |
|
|
Term
| Name the coenzyme that glycogen phosphorylase requires as a catalytic cofactor, and the vitamin from which it is derived |
|
Definition
| Pyridoxal (aldehyde) phosphate (PLP) derived from B6 Pyridoxine, and plays a large role in AA metabolism |
|
|
Term
| What is the function of phosphoglucomutase? |
|
Definition
| Phosphoglucomutase converts glucose 1-P to glucose 6-P and back (reversible) |
|
|
Term
| Where does protein phosphorylation happen on a molecule? |
|
Definition
|
|
Term
| Roughly how often does glycogen branch? Logically then as well what percent of glycogen is branched? |
|
Definition
| Glycogen has a branch roughly every 10 glucose rings and thus roughly 10% of its glucose rings are branched |
|
|
Term
| Explain the need for a branching enzyme in glycogenesis |
|
Definition
| Glycogen synthase can’t make new branches, but only add new glucose rings. Branching enzyme works as a 4:6 transferase to make new branches on glycogen. |
|
|
Term
| Explain why it is advantageous for glycogenolysis and glycogenesis to require some enzymes that the other pathway does not require |
|
Definition
| The pathway could not be regulated and would be a product of equilibrium if it was the same both ways. One can be activated while the other is inhibited. |
|
|
Term
| Describe how glycogenesis and glycogenolysis are not exact reversals of each other |
|
Definition
| Many different enzymes are used in the breakdown or buildup of glycogen. (degradation enzymes vs synthesis enzymes) Debrancher enzyme vs branching enzyme, glycogen phosphorylase vs glycogen synthase, the use of UTP and UDP-G in glycogenesis, glucose 6-phosphotase vs [hexokinase (muscle) or glucokinase (liver)] |
|
|
Term
| Explain why it is beneficial for glucagon signals to stimulate both glycogenolysis and gluconeogenesis in liver cells |
|
Definition
| Glucagon means the blood needs glucose, both glycogenolysis and gluconeogenesis make glucose and accomplish this goal |
|
|
Term
| What is the general function of a mutase? |
|
Definition
| change the position of an x group (often a phosphate group) on a molecule |
|
|
Term
| What is the general function of an isomerase? |
|
Definition
| Changes isomer form; catalyzes reaction that interconverts an aldose and its corresponding ketose (always reversible). ie: Glucose ←→ Fructose |
|
|
Term
Gluconeogenesis Steps (13)
&
Glycerol to DHAP (3) |
|
Definition
P. 567
Lactate via lactate dehydrogenase (NAD+ to NADH) or Alanine/AAs --> Pyruvate -pyruvate carboxylase-> OAA -aspartate transaminase-> aspartate out of matrix --> OAA -PEPCK & GTP to GDP-> PEP <-Enolase-> 2-Phosphoglycerate <-Phosphoglyceromutase-> 3-Phosphoglycerate <-ATP to ADP phosphoglycerate kinase-> 1,3-Bisphosphoglycerate <-H+ in Pi out NAD+ to NADH via Glyceraldehyde 3-P dehydrogenase-> Glyceraldehyde 3-P + DHAP <-Aldolase-> Fructose 1,6-phosphate -Fructose bis-phosphotase + Pi-> Fructose 6-phosphate -phosphoglucose isomerase-> Glucose 6 Phosphate -Glucose 6-phosphotase + Pi-> Glucose
---
Glycerol -ADP to ATP-> Glycerol 3 phosphate -NAD+ to NADH-> DHAP <-Triosephosphate isomerase-> Glyceraldehyde 3-phosphate |
|
|
Term
|
Definition
P. 405
D-Glucose --Hexokinase (in muscle) or glucokinase (in liver) + ATP to ADP--> Glucose 6-P <--Phosphoglucose isomerase--> Fructose 6-P --ATP to ADP + PKF-1--> Fructose 1,6-bis-P <--Aldol cleavage via Aldolase--> DHAP (<--Triphosphotate Isomerase-->) 2 of each molecule from now on starting with Glyceraldehyde 3-P <--Pi attaches, NAD+ to NADH + H+ via glyceraldehyde 3-P dehydrogenase--> 1,3-bis-phosphoglycerate <--ADP to ATP via phosphoglycerate kinase--> 3-phosphoglycerate <--phosphoglyceromutase--> 2-phosphoglycerate <--enolase + Removal of H2O--> PEP --ADP to ATP via pyruvate kinase--> (2)Pyruvates |
|
|
Term
| What are the general 4 different metabolic pathways that Glucose 6-P can take? |
|
Definition
| Glycolysis, Pentose Phosphate pathway, Glycogen Synthesis, Other Pathways |
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