BIOCHEMISTRY 3613
Exam 5 - December 6, 2002 Name:
Multiple choice ( 3 points each):
1. Which of the following unsaturated fatty acids is considered essential for man and most animals?
(a) palmitoleic (16:1n-9)
(b) oleic (18:1n-9)
(c) linoleic (18:2n-6)
(d) arachidonic (20:4n-6)
2. Which of the following is/are synthesized from arachidonic acid?
(a) prostaglandins
(b) thromboxanes
(c) leukotrines
(d) all of the above
3. Beta-oxidation of an 18 carbon fatty acid would produce 9 acetyl CoAs and
(a) 7 FADH2 plus 7 NADH
(b) 8 FADH2 plus 8 NADH
(c) 7 FADH2 plus 7 NADPH
(d) 8 FADH2 plus 8 NADPH
4. Which of the following is bound to the fatty acid during each step of beta oxidation?
(a) coenzyme A (CoASH)
(b) carnitine
(c) AMP
(d) acyl carrier protein (ACP)
5. Which of the following is able to cross the inner mitochondrial membrane?
(a) fatty acyl-CoA
(b) acetyl-CoA
(c) fatty acyl-carnitine
(d) fatty acyl-ACP
6. Which of the following is bound to the fatty acid during each step of fatty acid synthesis via the malonyl-CoA pathway?
(a) coenzyme A (CoASH)
(b) carnitine
(c) AMP
(d) acyl carrier protein (ACP)
7. Ketone body synthesis occurs exclusively in the
(a) kidney
(b) brain
(c) liver
(d) skeletal muscle
8. Which of the following intermediates becomes limiting (very low in concentration) and thus causes ketosis to develop
(a) acetyl-CoA
(b) pyruvate
(c) oxaloacetate
(d) citrate
9. Which of the following statements about ketone bodies is FALSE?
(a) Acetoacetate, beta-hydroxybutyrate and acetate are ketone bodies.
(b) The heart can use ketone bodies as an energy source.
(c) Ketone body levels in the blood increase during starvation.
(d) Low levels of ketone bodies are usually present in the blood.
10. A transamination reaction involving alanine and -keto glutarate as substrates will produce
(a) pyruvate and glutamic acid
(b) oxaloacetate and glutamic acid
(c) pyruvate and aspartic acid
(d) oxaloacetate and aspartic acid
11. Urea synthesis in mammals takes place in:
(a) kidney
(b) liver
(c) skeletal muscle
(d) small intestine
12. If a person's urine contains unusually high concentrations of urea, which of the following diets has her or she probably been eating recently?
(a) very high carbohydrate, very low protein
(b) very low carbohydrate, very high protein
(c) very high fat, very low protein
(d) very high fat, high carbohydrate, no protein
13. Albinism is caused by a deficiency in an enzyme involved in the metabolism of
(a) phenylalanine
(b) tryptophan
(c) leucine
(d) tyrosine
14. Which of the following amino acids is considered ketogenic only?
(a) threonine
(b) leucine
(c) isoleucine
(d) glycine
15. In the synthesis of urea in the urea cycle, one nitrogen of the urea comes from ammonia whereas the other comes directly from
(a) glycine
(b) glutamine
(c) alanine
(d) aspartic acid
16. In aquatic animals, excess nitrogen from the breakdown of amino acids is excreted as
(a) ammonia
(b) urea
(c) uric acid
(d) glutamine
17. Alkaptonuria is a genetic disease involving the metabolism of
(a) tryptophan
(b) leucine
(c) tyrosine
(d) phenylalanine
18. Which of the following amino acids is both glucogenic and ketogenic?
(a) lysine
(b) threonine
(c) isoleucine
(d) glycine
19. Maple syrup urine disease is a genetic disease involving the metabolism of
(a) urea
(b) ketone bodies
(c) uric acid
(d) branched chain amino acids
20. Nonessential amino acids:
(a) are not utilized in mammalian proteins
(b) may be substituted with other amino acids in proteins
(c) can be synthesized in humans as well as in bacteria
(d) are synthesized by plants and bacteria, but not by humans
21. Which of the following groups of amino acids are consider essential for the young growing animal?
(a) glycine, glutamine, aspartic acid, asparagine
(b) phenylalanine, histidine, methionine, tryptophan
(c) valine, threonine, alanine, tryosine
(d) lysine, leucine, isoleucine, serine
22. Which of the following amino acids is not directly involved in the synthesis of the purine ring?
(a) glutamine
(b) aspartate
(c) alanine
(d) glycine
23. The end product of purine catabolism in man is:
(a) uric acid
(b) urea
(c) allantoin
(d) allantoic acid
24. The salvage pathway system discussed in class is used to recycle:
(a) uric acid
(b) purines
(c) pyrimidines
(d) amino acids
25. A drug used to treat gout in man is:
(a) allantoin
(b) allopurinol
(c) fluorouracil
(d) azaserine
26. The end product of purine biosynthesis is:
(a) inosinic acid (IMP)
(b) orotidylic acid (OMP)
(c) xanthylic acid (XMO)
(d) orotic acid
27. The end product of pyrimidine biosynthesis is:
(a) inosinic acid (IMP)
(b) orotidylic acid (OMP)
(c) xanthylic acid (XMP)
(d) orotic acid
28. Precursors for the biosynthesis of the pyrimidine ring system include
(a) glutamate, NH3, and CO2
(b) glycine, glutamine, CO2, and aspartate
(c) glycine and succinyl-CoA
(d) glutamine, CO2 and aspartate
29. Beta-alanine is one of the end products of the catabolism of
(a) adenine
(b) guanine
(c) uracil
(d) thymine
30. Methotrexate is used to treat cancer because it
(a) inhibits the use of glutamine in purine synthesis
(b) inhibits the enzyme needed for thymidylate synthesis
(c) inhibits the use of folic acid in thymidylate synthesis
(d) none of the above
31. The metabolic process of DNA synthesis is called
(a) duplication
(b) replication
(c) transcription
(d) translation
32. The metabolic process of RNA synthesis is called
(a) duplication
(b) replication
(c) transcription
(d) translation
33. The metabolic process of protein synthesis is called
(a) duplication
(b) replication
(c) transcription
(d) translation