Question :
31.Which of the following statements concerning lipogenesis correct?
a.It occurs in : 1309722
31.Which of the following statements concerning lipogenesis is correct?
a.It occurs in the cytosol of a cell.
b.It involves a multienzyme complex rather than a series of individual enzymes.
c.It is dependent on the oxidizing agents FAD and NAD+.
d.More than one correct response.
e.No correct response.
32.Which of the following statements concerning the chain elongation phase of fatty acid biosynthesis is correct?
a.Step 1 involves a condensation reaction.
b.Step 2 involves a hydration reaction.
c.Step 3 involves a dehydrogenation reaction.
d.More than one correct response.
e.No correct response.
33.Which of the following is an intermediate in the process of lipogenesis?
a.isopentenyl pyrophosphate
b.malonyl ACP
c.oxaloacetate
d.more than one correct response
e.no correct response
34.Which of the following pairings of information about intermediates in the biosynthesis of cholesterol is correct?
a.mevalonate; a C5 molecule
b.squalene; a C20 molecule
c.lanosterol; a C30 molecule
d.more than one correct response
e.no correct response
35.Which of the following is a possible fate for the acetyl CoA produced from the degradation of a fatty acid?
a.conversion to pyruvate
b.ketone body formation
c.cholesterol biosynthesis
d.more than one correct response
e.no correct response
Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
36.Statements:
(1) Both TAG emulsification and TAG digestion occur in the small intestine.
(2) On an equal-mass basis, fatty acids produce more than twice as much ATP per gram as carbohydrates (glucose).
(3) The “opposite” processes of lipogenesis and fatty acid oxidation cannot occur at the same time.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
37.Statements:
(1) The ?-oxidation pathway involves a repetitive series of four reactions.
(2) Triacylglycerol mobilization is a hydrolysis process that occurs in adipose tissue.
(3) ATP and ACP have similar functions within the human body.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
38.Statements:
(1) The process by which ketone bodies are produced from acetyl CoA is called ketosis.
(2) The number of “turns” in the ?-oxidation pathway needed to process an 18-carbon saturated fatty acid is nine.
(3) Glycerol metabolism involves production of dihydroxyacetone phosphate, which then enters the glycolysis pathway.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
39.Statements:
(1) Initial triacylglycerol digestion usually produces monoacylglycerols rather than glycerol itself.
(2) Fatty acids are the preferred fuel for “running” the heart (cardiac muscle) and the brain.
(3) The ketone body acetoacetate is the “parent” compound for the other four ketone bodies.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
40.Statements:
(1) The number of acetyl CoA molecules produced in the ?-oxidation pathway is equal to half the number of carbon atoms in the fatty acid that is processed.
(2) A fatty acid micelle is a lipoprotein that transports TAGs from the intestinal walls to the bloodstream.
(3) Associated with the conversion of acetyl CoA to malonyl CoA, in lipogenesis, is the production of a carbon dioxide molecule.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
41.Statements:
(1) The products of the first two stages of cholesterol biosynthesis are, respectively, mevalonate (C6) and isopentenyl pyrophosphate (C5).
(2) Over 90 percent of total dietary lipids are triacylglycerols.
(3) The activation stage of fatty acid oxidation involves both CoA and ATP.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
42.Statements:
(1) The functional group change sequence “alkane-alkene-primary alcohol-ketone” occurs during each “turn” of the ?-oxidation pathway.
(2) Squalene and lanosterol, intermediates in cholesterol biosynthesis, contain more carbon atoms than does cholesterol.
(3) The acetyl CoA needed for lipogenesis is shuttled from mitochondria to the cytosol via a citrate shuttle.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
43.Statements:
(1) When the amount of acetyl CoA is excessive compared with the amount of oxaloacetate available to react with it, ketone body formation occurs.
(2) The transport stage of fatty acid oxidation involves the shuttle molecule acyl carnitine.
(3) As a part of digestion of lipids, enzymes in bile help “solubilize” the lipids.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
44.Statements:
(1) The ketone body acetoacetate lowers blood pH because of the presence of a carboxyl (acid) group in its structure.
(2) Two products of the initial “turn” in the ?-oxidation pathway are acetyl CoA and a fatty acid that contains two more carbon atoms than the reactant fatty acid.
(3) Fatty acids produced through lipogenesis cannot contain more than 14 carbon atoms.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
(1) The human body, in the resting state, burns more fat than carbohydrate.
(2) The initial stages of exercise are fueled primarily by glucose.
(3) Statins lower plasma concentrations of LDL by inhibiting cholesterol synthesis in the liver.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
