Chap 17 foster biochem

17. Which compound is an intermediate of the -oxidation of fatty acids? A) CH3—(CH2)20—CO—COOH B) CH3—CH2—CO—CH2—CO—OPO32- C) CH3—CH2—CO—CH2—OH D) CH3—CH2—CO—CO—S—CoA E) CH3—CO—CH2—CO—S—CoA

E) CH3—CO—CH2—CO—S—CoA

27. Which of the following is not true about Vitamin B12? A Vitamin B12 contains a porphyrin ring. B) Vitamin B12 contains a carbon-cobalt bond. C) Vitamin B12 readily undergoes homolytic bond cleavage. D) Deficiency of Vitamin B12 causes pernicious anemia. E) Vitamin B12 catalyzes hydrogen atom exchange with solvent H2O.

E) Vitamin B12 catalyzes hydrogen atom exchange with solvent H2O.

20. If an aerobic organism (e.g., the bacterium E. coli) were fed each of the following four compounds as a source of energy, the energy yield per mole from these molecules would be in the order: A) alanine > glucose > palmitate B) glucose > alanine > palmitate C) glucose > palmitate > alanine D) palmitate > alanine > glucose E) palmitate > glucose > alanine

E) palmitate > glucose > alanine

22. The following fatty acid, in which the indicated carbon is labeled with 14C, is fed to an animal: 14CH3(CH2)9COOH After allowing 30 minutes for fatty acid beta-oxidation, the label would most likely be recovered in: A) acetyl-CoA. B) beta-hydroxy butyryl-CoA. C) both acetyl-CoA and propionyl-CoA. D) palmitoyl-CoA. E) propionyl-CoA.

E) propionyl-CoA.

18. The conversion of palmitoyl-CoA (16:0) to myristoyl-CoA (14:0) and 1 mol of acetyl-CoA by the -oxidation pathway results in the net formation of: A) 1 FADH2 and 1 NADH. B) 1 FADH2 and 1 NADPH. C) 1 FADH2, 1 NADH, and 1 ATP. D) 2 FADH2 and 2 NADH. E) 2 FADH2, 2 NADH, and 1 ATP.

A) 1 FADH2 and 1 NADH.

5. Transport of fatty acids from the cytoplasm to the mitochondrial matrix requires: A) ATP, carnitine, and coenzyme A. B) ATP, carnitine, and pyruvate dehydrogenase. C) ATP, coenzyme A, and hexokinase. D) ATP, coenzyme A, and pyruvate dehydrogenase. E) carnitine, coenzyme A, and hexokinase.

A) ATP, carnitine, and coenzyme A.

16. The balanced equation for the degradation of CH3(CH2)10COOH via the beta-oxidation pathway is:

A) CH3(CH2)10COOH + 5FAD + 5NAD+ + 6CoA—SH + 5H2O + ATP -->6 Acetyl-CoA + 5FADH2 + 5NADH + 5H+ + AMP + PPi

6. Fatty acids are activated to acyl-CoAs and the acyl group is further transferred to carnitine because: A) acyl-carnitines readily cross the mitochondrial inner membrane, but acyl-CoAs do not. B) acyl-CoAs easily cross the mitochondrial membrane, but the fatty acids themselves will not. C) carnitine is required to oxidize NAD+ to NADH. D) fatty acids cannot be oxidized by FAD unless they are in the acyl-carnitine form. E) None of the above is true.

A) acyl-carnitines readily cross the mitochondrial inner membrane, but acyl-CoAs do not.

1. Lipoprotein lipase acts in: A) hydrolysis of triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues. B) intestinal uptake of dietary fat. C) intracellular lipid breakdown of lipoproteins. D) lipoprotein breakdown to supply needed amino acids. E) none of the above.

A) hydrolysis of triacylglycerols of plasma lipoproteins to supply fatty acids to various tissues.

12. A) 1 and 5 only B) 1, 2, and 5 C) 1, 2, and 6 D) 1, 3, and 5 E) 5 only

B) 1, 2, and 5

13. Complete oxidation of 1 mole of which fatty acid would yield the most ATP? A) 16-carbon saturated fatty acid B) 18-carbon mono-unsaturated fatty acid C) 16-carbon mono-unsaturated fatty acid D) 16-carbon poly-unsaturated fatty acid E) 14-carbon saturated fatty acid

B) 18-carbon mono-unsaturated fatty acid

24. In the disease sprue, vitamin B12 (cobalamin) is poorly absorbed in the intestine, resulting in B12 deficiency. If each of the following fatty acids were in the diet, for which one would the process of fatty acid oxidation be most affected in a patient with sprue? A) CH3(CH2)10COOH B) CH3(CH2)11COOH C) CH3(CH2)12COOH D) CH3(CH2)14COOH E) CH3(CH2)18COOH

B) CH3(CH2)11COOH

25. Which enzyme is the major regulatory control point for beta-oxidation? A) Pyruvate carboxylase B) Carnitine acyl transferase I C) Acetyl CoA dehydrogenase D) Enoyl CoA isomerase E) Methylmalonyl CoA mutase

B) Carnitine acyl transferase I

8. Which of these is able to cross the inner mitochondrial membrane? A) Acetyl-CoA B) Fatty acyl-carnitine C) Fatty acyl-CoA D) Malonyl-CoA E) None of the above can cross.

B) Fatty acyl-carnitine

29. When comparing the beta-oxidation and omega-oxidation pathways, which one of the following statements is correct? A) beta-oxidation and omega-oxidation occur in the cytoplasm. B) beta-oxidation occurs at the carboxyl end of the fatty acid whereas omega-oxidation occurs at the methyl end. C) beta-oxidation occurs at the methyl end of the fatty acid, whereas omega-oxidation occurs at the carboxyl end. D) beta-oxidation occurs mainly in the cytoplasm, whereas omega-oxidation occurs mainly in the mitochondria. E) beta-oxidation occurs mainly in the mitochondria, whereas omega-oxidation occurs mainly in the cytoplasm.

B) beta-oxidation occurs at the carboxyl end of the fatty acid whereas omega-oxidation occurs at the methyl end.

2. Free fatty acids in the bloodstream are: A) bound to hemoglobin. B) carried by the protein serum albumin. C) freely soluble in the aqueous phase of the blood. D) nonexistent; the blood does not contain free fatty acids. E) present at levels that are independent of epinephrine.

B) carried by the protein serum albumin.

11. Saturated fatty acids are degraded by the stepwise reactions of beta-oxidation, producing acetyl-CoA. Under aerobic conditions, how many ATP molecules would be produced as a consequence of removal of each acetyl-CoA? A) 2 B) 3 C) 4 D) 5 E) 6

C) 4

9. What is the correct order of function of the following enzymes of beta-oxidation? 1. Beta-Hydroxyacyl-CoA dehydrogenase 2. Thiolase 3. Enoyl-CoA hydratase 4. Acyl-CoA dehydrogenase A) 1, 2, 3, 4 B) 3, 1, 4, 2 C) 4, 3, 1, 2 D) 1, 4, 3, 2 E) 4, 2, 3, 1

C) 4, 3, 1, 2

19. Which of the following is not true regarding the oxidation of 1 mol of palmitate (16:0) by the beta-oxidation pathway? A) 1 mol of ATP is needed. B) 8 mol of acetyl-CoA are formed. C) 8 mol of FADH2 are formed. D) AMP and PPi are formed. E) The reactions occur in the mitochondria

C) 8 mol of FADH2 are formed.

30. Ketone bodies are formed in the liver and transported to the extrahepatic tissues mainly as: A) acetoacetyl-CoA. B) acetone. C) beta-hydroxybutyric acid. D) beta-hydroxybutyryl-CoA. E) lactic acid.

C) beta-hydroxybutyric acid.

4. The glycerol produced from the hydrolysis of triacylglycerides enters glycolysis as: A) glucose. B) glucose-6-phosphate. C) dihydroxyacetone phosphate. D) pyruvate. E) glyceryl CoA.

C) dihydroxyacetone phosphate

7. Carnitine is: A) a 15-carbon fatty acid. B) an essential cofactor for the citric acid cycle. C) essential for intracellular transport of fatty acids. D) one of the amino acids commonly found in protein. E) present only in carnivorous animals.

C) essential for intracellular transport of fatty acids.

3. The role of hormone-sensitive triacylglycerol lipase is to: A) hydrolyze lipids stored in the liver. B) hydrolyze membrane phospholipids in hormone-producing cells. C) hydrolyze triacylglycerols stored in adipose tissue. D) synthesize lipids in adipose tissue. E) synthesize triacylglycerols in the liver.

C) hydrolyze triacylglycerols stored in adipose tissue.

26. The metabolite that regulates the activity of carnitine acyl transferase I is: A) acetyl-CoA. B) carnitine-CoA. C) malonyl-CoA. D) NADH. E) CoA.

C) malonyl-CoA.

10. If the 16-carbon saturated fatty acid palmitate is oxidized completely to carbon dioxide and water (via the beta-oxidation pathway and the citric acid cycle), and all of the energy-conserving products are used to drive ATP synthesis in the mitochondrion, the net yield of ATP per molecule of palmitate is: A) 3. B) 10. C) 25. D) 108. E) 1000.

D) 108.

21. Which of the following is (are) true of the beta-oxidation of long-chain fatty acids? 1. The enzyme complex that catalyzes the reaction contains biotin. 2. FADH2 serves as an electron carrier. 3. NADH serves as an electron carrier. 4. Oxidation of an 18-carbon fatty acid produces six molecules of propionyl-CoA. 5. Oxidation of a 15-carbon fatty acid produces at least one propionyl-CoA.

D) 2, 3, and 5

14. Which of the following statements apply (applies) to the -oxidation of fatty acids? 1. The process takes place in the cytosol of mammalian cells. 2. Carbon atoms are removed from the acyl chain one at a time. 3. Before oxidation, fatty acids must be converted to their CoA derivatives. 4. NADP+ is the electron acceptor. 5. The products of -oxidation can directly enter the citric acid cycle for further oxidation.

D) 3 and 5 only

28. During beta-oxidation of fatty acids, ___________ is produced in peroxisomes but not in mitochondria. A) acetyl-CoA B) FADH2 C) H2O D) H2O2 E) NADH

D) H2O2

15. Which of the following statements concerning the beta-oxidation of fatty acids is true? A) About 1200 ATP molecules are ultimately produced per 20-carbon fatty acid oxidized. B) One FADH2 and two NADH are produced for each acetyl-CoA. C) The free fatty acid must be carboxylated in the position by a biotin-dependent reaction before the process of -oxidation commences. D) The free fatty acid must be converted to a thioester before the process of -oxidation commences. E) Two NADH are produced for each acetyl-CoA.

D) The free fatty acid must be converted to a thioester before the process of -oxidation commences.

31. The major site of formation of acetoacetate from fatty acids is the: A) adipose tissue. B) intestinal mucosa. C) kidney. D) liver. E) muscle.

D) liver.

23. The carbon atoms from a fatty acid with an odd number of carbons will enter the citric acid cycle as acetyl-CoA and: A) butyrate. B) citrate. C) malate. D) succinyl-CoA. E) alpha-ketoglutarate.

D) succinyl-CoA.