Term
| What are the common chain lengths for fatty acids found in milk? |
|
Definition
|
|
Term
| What are the two essential fatty acids? |
|
Definition
| Linoleic and Linolenic Acid |
|
|
Term
| What protein is used to transport free fatty acids? |
|
Definition
|
|
Term
| What enzyme is responsible for hydrolysis of ester linkages in dietary TGs prior to absorption into the circulation? |
|
Definition
|
|
Term
| What stimulates release of bile salts from the gall bladder and where do they end up? |
|
Definition
| Cholecystokinin; small intestine |
|
|
Term
| Where are chylomicrons synthesized, and where do they end up? |
|
Definition
| Intestinal cells; lymph for transport to blood via thoracic duct |
|
|
Term
| What is the ultimate fate of bile salts? |
|
Definition
| Reabsorbed in the ileum and recycled to liver |
|
|
Term
| What is the main function of colipase? |
|
Definition
| To relieve bile acid inhibition of lipase |
|
|
Term
| What effect does bicarbonate have on lipase activity? |
|
Definition
| By raising the intestinal pH it increases lipase activity |
|
|
Term
| What is the main clinical use of Oral Lipase Inhibitors? |
|
Definition
| Decrease formation of chylomicrons; decrease levels of TG in blood; useful in patients that cannot utilize chylomicron |
|
|
Term
| Where are TGs reassembled in the intestinal cells, and what enzyme activates fatty acids for TG synthesis? |
|
Definition
| Reassembly occurs in the smooth ER; fatty acyl CoA synthase activates fatty acids |
|
|
Term
| What structural scaffolding protein is the core of chylomicron synthesis? |
|
Definition
| Apo B-48 (added in rough ER) |
|
|
Term
| Where are chylomicrons assembled? |
|
Definition
|
|
Term
| What is the fate of short and medium chain fatty acids? |
|
Definition
Instead of being packaged into chylomicrons they diffuse across cell membranes of intestinal cells directly into the portal vein
TRANSPORTED BOUND TO SERUM ALBUMIN IN BLOOD |
|
|
Term
| What is the consequence of a deficiency in LPL (lipoprotein lipase)? |
|
Definition
| Decreased ability to deliver LONG CHAIN fatty acids to cells via chylomicrons and VLDLs |
|
|
Term
| What is the function of LDLs? |
|
Definition
| Deliver cholesterol to liver and tissues that have large cholesterol needs |
|
|
Term
| What is the function of HDLs? |
|
Definition
| To transport cholesterol from membranes of tissues BACK TO THE LIVER |
|
|
Term
| What is the structural scaffolding protein of VLDLs? |
|
Definition
|
|
Term
| What process makes Apo B-48 from the Apo B-100 gene? |
|
Definition
| RNA Editing via a STOP CODON in intestinal cells |
|
|
Term
| What effect does insulin have on LPL synthesis? |
|
Definition
|
|
Term
| What is required on the lipoprotein particle to activate Lipoprotein Lipase (LPL)? |
|
Definition
|
|
Term
| What is the function of Apo E? |
|
Definition
| Apo E is the ligand for the chylomicron REMNANT receptor in the liver, which allows remnants to be taken up after lipid cargo is delivered to tissues |
|
|
Term
| What happens if ApoC II is defective? |
|
Definition
| Hyperlipidemia (no triggering of LPL, cannot get chylomicron/VLDL fatty acids out of blood and into tissue) |
|
|
Term
| Why is gastric lipase more important in lipid digestion in neonates than in adults? |
|
Definition
| Lipase is more active at a higher pH; adults have a more acidic pH |
|
|
Term
| Where do chylomicrons acquire Apo CII? |
|
Definition
|
|
Term
| What is the carbon source for most fatty acid synthesis? |
|
Definition
| Main source is carbohydrate |
|
|
Term
| Where is acetyl CoA synthesized to eventually build fatty acids? |
|
Definition
|
|
Term
| What essential intermediate allows Acetyl CoA to leave the mitochondria and enter the cytosol? |
|
Definition
|
|
Term
| What is the immediate donor of the 2 carbon acetyl units of fatty acids? |
|
Definition
|
|
Term
| What enzyme makes malonyl CoA? |
|
Definition
|
|
Term
| What is the rate limiting step of fatty acid synthesis? |
|
Definition
| The synthesis of Malonly CoA by Acetyl CoA Carboxylase |
|
|
Term
| What is the reducing factor used by fatty acid synthase? |
|
Definition
|
|
Term
| Where are fatty acids synthesized? |
|
Definition
| In the cytosol by fatty acid synthase |
|
|
Term
| What two molecules are condensed to build fatty acids, and what is the final product? |
|
Definition
| Malonyl CoA + Acetyl Co A to make PALMITIC ACID |
|
|
Term
| What two molecules are condensed to form citrate? |
|
Definition
| Acetyl CoA and Oxaloacetate |
|
|
Term
| What enzyme breaks citrate into its component parts, and what are those parts? |
|
Definition
| Citrate Lyase; Oxaloacetate and Acetyl CoA |
|
|
Term
| How many NADPH are required per acetate unit added to a fatty acid during synthesis? |
|
Definition
|
|
Term
| Where does the NADPH used in fatty acid synthesis come from? |
|
Definition
| Malic Enzyme and the Pentose Phosphate Pathway |
|
|
Term
| What are the two actions of malic enzyme? |
|
Definition
GENERATE NADPH FOR FATTY ACID SYNTHESIS
-convert malate to pyruvate for shuttling back into mitochondria |
|
|
Term
| What are the 3 things required for the function of Acetyl CoA Carboxylase, and what is the final product of this enzyme? |
|
Definition
1)ATP
2)BIOTIN BIOTIN BIOTIN BIOTIN
3)CO2
Final Product= Malonyl CoA |
|
|
Term
What is the effect of each of the following on the action of Acetly CoA Carboxylase?
-Citrate
-Palmitoyl CoA
-Insulin
-Glucagon
-Epinephrine |
|
Definition
-Citrate-INCREASE ACTIVITY
-Palmitoyl CoA- DECREASE ACTIVITY
-Insulin- ACTIVATES
-Glucagon- DEACTIVATES
-Epinephrine- DEACTIVATES |
|
|
Term
| What are the two important amino acid residues used by Fatty Acid Synthase, and what do they do? |
|
Definition
Phosphopantethine and Cysteine
-form thioesters with developing fatty acyl chain
-the chain moves between these 2 sulfhydryl residues as it elongates |
|
|
Term
| Where does elongation of fatty acids occur and what does it require? |
|
Definition
Smooth ER; NADPH and Malonyl CoA
(most often Palmitate (C16) to Stearate (C18) |
|
|
Term
| Where does desaturation of Fatty Acids occur, and what is required? |
|
Definition
| Endoplasmic Reticulum; O2, NADH, and cyt b5 (using Fe) |
|
|
Term
| What is the restriction on human desaturase enzymes, and what does it mean for dietary fatty acid intake? |
|
Definition
| Human desaturases cannot introduce double bonds between Carbon 9 and the methyl end of a FA chain, so LINOLEIC and LINOLENIC ACIDS ARE ESSENTIAL |
|
|
Term
| What are the two essential elements of Triglyceride Synthesis, and what do they form? |
|
Definition
| Glycerol-3-phosphate and Fatty Acyl CoA; they form Phosphatidic Acid |
|
|
Term
| What liver enzyme catalyzes the formation of Glycerol-3-phosphate from glucose? |
|
Definition
|
|
Term
| From what does adipose tissue make glycerol-3-phosphate? |
|
Definition
|
|
Term
| What enzyme in adipose tissue that breaks down Triglycerides is activated by low levels of insulin? |
|
Definition
|
|
Term
| What is the backbone of glycerophospholipids? |
|
Definition
|
|
Term
| What is the backbone of sphingolipids? |
|
Definition
|
|
Term
| What is the fatty-acid like component of sphingomyelin? |
|
Definition
| Sphingosine (contains a nitrogenous portion) |
|
|
Term
| What family of compounds makes lung surfactant? |
|
Definition
|
|
Term
| What is the building block for phospholipids? |
|
Definition
|
|
Term
| What class of compounds is important in antigenic determinants of blood group substances? |
|
Definition
|
|
Term
| What is the main function of sphingomyelin? |
|
Definition
| Structural component of the outer leaflet of nerve and the myelin sheath |
|
|
Term
| What is Zellwegers Syndrome? |
|
Definition
A state of non-functioning peroxisomes
-INABILITY TO SYNTHESIZE PLASMALOGENS |
|
|
Term
| What is the action of Phospholipase A1? |
|
Definition
| To cleave the first fatty acid (1-acyl) from backbone |
|
|
Term
| What is the action of Phospholipase A2? |
|
Definition
| To cleave the second fatty acid (2-acyl) from backbone (as in release of Arachidonic Acid) |
|
|
Term
| What is the action of Phospholipase C? |
|
Definition
| To cleave the phosphate group, with its head group, off of the backbone |
|
|
Term
| What is the action of Phospholipase D? |
|
Definition
| To cleave JUST THE HEAD GROUP (not phosphate) from the backbone, leaving Phosphatidic Acid |
|
|
Term
| What enzyme is deficient in Tay Sachs disease? |
|
Definition
|
|
Term
| What enzyme is deficient in Gauchers Disease? |
|
Definition
|
|
Term
| What enzyme is deficient in Neimann-Pick disease? |
|
Definition
|
|
Term
| What enzyme catalyzes the hydrolysis of PIP2 to produce IP3 and DAG (stimulating PKC)? |
|
Definition
|
|
Term
| What major lung surfactant is deficient in respiratory distress syndrome? |
|
Definition
|
|
Term
| Why does a lack of surfactant cause respiratory distress? |
|
Definition
| Surface tension causing sac collapse |
|
|
Term
| What ratio do we use as a measure of lung maturity in neonates? |
|
Definition
| Lecithin to Sphingomyelin Ratio |
|
|
Term
| How do you treat respiratory distress syndrome? |
|
Definition
Administer CORTICOSTERIODS within 48-72 hours before delivery to stimulate surfactant production
-administer oxygen |
|
|
Term
| What is the MOST DIRECT source of Acetyl CoA for biosynthesis of fatty acids? |
|
Definition
|
|
Term
| Where are the primary sites of cholesterol synthesis? |
|
Definition
| LIVER, adrenals, gonads, intestine, placenta |
|
|
Term
| What effect does cholesterol have on cell membranes? |
|
Definition
|
|
Term
| In what form can most plasma cholesterol be found? |
|
Definition
|
|
Term
| Where does cholesterol synthesis occur? |
|
Definition
| In the CYTOPLASM, with enzymes in the cytosol and in the membrane of the ER |
|
|
Term
| What is the rate limiting step of cholesterol synthesis? |
|
Definition
| HMG-CoA Reductase converting Acetyl CoA to Mevalonate |
|
|
Term
| What enzyme is the target of cholesterol drug therapy, and what class of drugs are these? |
|
Definition
| HMG CoA Reductase; STATINS |
|
|
Term
How do the following effect the action of HMG-CoA Reductase?
-Cholesterol
-Mevalonate
-Statin Drugs |
|
Definition
-Cholesterol- inhibits
-Mevalonate- inhibits
-Statins- inhibit |
|
|
Term
| What enzyme is the key regulatory point in cholesterol biosynthesis and where is it located? |
|
Definition
| HMG CoA Reductase; ER Membrane |
|
|
Term
| What are isoprenoids precursors to? |
|
Definition
| (activated 5 carbon units) precursors to cholesterol, dolichol, heme, and CoQ |
|
|
Term
| What effect does insulin have on cholesterol synthesis? |
|
Definition
|
|
Term
| What effect does glucagon have on cholesterol synthesis? |
|
Definition
|
|
Term
| What is the major lipoprotein on HDLs? |
|
Definition
|
|
Term
| What is ACAT? (Acyl:cholesterol acyltransferase) |
|
Definition
| The enzyme that synthesizes cholesterol esters in TISSUES |
|
|
Term
| What is LCAT? (Lecithin:cholesterol acyltransferase) |
|
Definition
| The enzyme that synthesizes cholesterol esters in BLOOD |
|
|
Term
| What are 3 effects of high cholesterol on cellular regulation of cholesterol? |
|
Definition
-LDL receptors decrease
-HMG CoA Reductase activity decreases
-ACAT storage of cholesterol esters INCREASES |
|
|
Term
| What are the 2 functions of HDL? |
|
Definition
-transfer ApoCII and ApoE to chylomicrons and VLDL
-scavenge cholesterol from tissues and transfer it to LDLs |
|
|
Term
| What stimulates LCAT (and PCAT)? |
|
Definition
| ApoA-1 on the HDL particle |
|
|
Term
| What is the function of Cholesterol Ester Transfer Protein (CETP)? |
|
Definition
| To transfer cholesterol esters to VLDLs from HDLs and to transfer TGs from VLDLs to HDLs |
|
|
Term
| What problem can arise with phagocytosis of oxidized LDL particles? |
|
Definition
| Atherosclerosis- Oxidized LDLs are recognized as foreign- the result is FOAM CELLS- fatty streaks on the tunica interna |
|
|
Term
| What is a possible cause of familial hypercholesterolemia? |
|
Definition
| Defective LDL receptor- LDLs hang around and get attacked by macrophages |
|
|
Term
| Name 3 types of Eicosanoids: |
|
Definition
| Prostaglandins, leukotrienes, thromboxanes |
|
|
Term
|
Definition
| A substance produced in one cell type that alters its own activity or the activity of cells of the same type |
|
|
Term
|
Definition
| A substance released from one cell type that alters the function of neighboring cells of a different type |
|
|
Term
| What enzyme releases arachidonic acid from membrane phospholipids? |
|
Definition
|
|
Term
| From what fatty acid is arachidonic acid synthesized? |
|
Definition
| Linoleic Acid (Essential Fatty Acid) |
|
|
Term
| What compounds are produced by Cyclooxygenase? |
|
Definition
| Prostaglandins and Thromboxanes |
|
|
Term
| What compounds are produced by Lipoxygenase? |
|
Definition
| HPETE, leukotrienes, HETE, lipoxins |
|
|
Term
| What compounds are produced by Cytochrome P450? |
|
Definition
| Epoxides (diHETE and HETE) |
|
|
Term
| What inhibits Cyclooxygenase? |
|
Definition
|
|
Term
|
Definition
| Stimulate platelet aggregation, cause vasoconstriction |
|
|
Term
| What are 2 Cox-2 inhibitors and what do they target? |
|
Definition
| Vioxx and Celebrex; Target inflammatory cells |
|
|
Term
| What is one IRREVERSIBLE inhibitor of cyclooxygenase? |
|
Definition
|
|
Term
| What are some functions of leukotrienes? |
|
Definition
| Vascular permeability, T-cell proliferation, interferon gamma, IL-1, IL-2 |
|
|
Term
| What do lipoxins stimulate? |
|
Definition
| Production of SUPEROXIDE for respiratory burst in leukocytes |
|
|
Term
| What line of treatment should be used for asthma attacks? |
|
Definition
| Glucocorticoids- suppress transcription and translatoin of Cyclooxygenase; induce the synthesis of proteins that inhibit the activity of Phospholipase A2; decrease synthesis of inflammatory mediators in bronchial tissues |
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