Row number: Name:
Multiple choice (3 points each)
1. Which of the following fatty acids can be synthesized by plants but not by animals?
(a) linoleic (18:2n-6)
(b) arachidonic (20:4n-6)
(c) oleic (18:1n-9)
(d) palmitoleic (16:1n-9)
2. Which of the following is NOT required for the synthesis of unsaturated fatty acids?
(a) molecular oxygen (O2)
(b) cytochrome b5
(c) ATP
(d) a mixed-function oxidase
3. Very low density lipoproteins transport
(a) non-esterified fatty acids to the liver
(b) medium chain non-esterified fatty acids via the lymphatic system
(c) non-esterified fatty acids to the adipose tissue
(d) triglyceride from the liver to the adipose tissue
4. Which of the following is(are) synthesized from arachidonic acid?
(a) prostaglandins
(b) thromboxanes
(c) leukotrines
(d) all of the above
5. Aspirin apparently helps to reduce heart attacks by inhibiting (a) phospholipid biosynthesis
(b) prostaglandin biosynthesis
(c) thromboxane biosynthesis
(d) leukotrine biosynthesis
6. Which of the following substances is an intermediate in the synthesis of both triglycerides and phospholipids?
(a) phosphatidic acid
(b) CDP-choline
(c) CDP-fatty acids
(d) phosphatidylinositol
7. Which of the following contains the highest percentage of cholesterol?
(a) LDL (low density lipoproteins)
(b) VLDL (very low density lipoproteins)
(c) HDL (high density lipoproteins)
(d) chylomicrons
8. In the synthesis of phosphatidylcholine from phosphatidylethanolamine, the methyl group donor is:
(a) acetyl CoA
(b) S-adenosylmethionine
(c) a tetrahydrofolate derivative
(d) choline
9. Which of the following is an intermediate in cholesterol
synthesis?
(a) -hydroxy-butyryl-CoA
(b) mevalonic acid
(c) malonyl CoA
(d) methylmalonyl CoA
10. Which of the following plasma lipoproteins contain the smallest amount of total protein?
(a) chylomicrons
(b) VLDL
(C) LDL
(d) HDL
11. Which of the following plasma lipoproteins contain the smallest amount of total cholesterol?
(a) chylomicrons
(b) VLDL
(c) LDL
(d) HDL
12. Which of the following hormones is NOT synthesized from cholesterol?
(a) glucocorticoids
(b) androgens
(c) prostaglandins
(d) mineralocorticoids
13. The coenzyme required for all transamination or aminotransferase reactions is derived from:
(a) riboflavin
(b) thiamin
(c) folic acid
(d) pyridoxine (vitamin B6)
14. Which of the following compounds serves to transport excess ammonia from muscle to liver for urea synthesis?
(a) glutamic acid
(b) aspartic acid
(c) glutamine
(d) glycine
15. Which of the following proteases activates the other proteases in the small intestine by acting on their respective zymogen?
(a) trypsin
(b) chymotrypsin
(c) enteropeptidase or enterokinase
(d) carboxypeptidase
16. Which of the following compounds DIRECTLY donates a nitrogen atom for the formation of urea via the urea cycle?
(a) glutamic acid
(b) aspartic acid
(c) alanine
(d) glycine
17. Which of the following is NOT an intermediates in the urea cycle?
(a) citrulline
(b) ornithine
(c) arginine
(d) carnitine
18. Which of the following compounds serves to regulate the urea cycle?
(a) N-acetyl aspartate
(b) glucagon
(c) N-acetyl glutamate
(d) urea
19. In aquatic animals, excess nitrogen from the breakdown of amino
acids is excreted as
(a) ammonia
(b) carbamoyl phosphate
(c) urea
(d) uric acid
20. In birds, excess nitrogen from the breakdown of amino acids is excreted as
(a) ammonia
(b) carbamoyl phosphate
(c) urea
(d) uric acid
21. In mammals, urea synthesis takes place in the
(a) kidney
(b) liver
(c) intestinal mucosa
(d) liver and kidney
22. Alkaptonuria is a genetic disease involving the metabolism of
(a) tryptophan
(b) phenylalanine
(c) tyrosine
(d) branched chain amino acids
23. Phenylketonuria (PKU) is a genetic disease involving the metabolism of
(a) tryptophan
(b) phenylalanine
(c) tyrosine
(d) branched chain amino acids
24. Albinism is a genetic disease involving the lack of melanin which is synthesized from
(a) tryptophan
(b) phenylalanine
(c) tyrosine
(d) branched chain amino acids
25. Which of the following forms of nitrogen is used directly by plants to synthesize amino acids?
(a) ammonium ions
(b) nitrogen gas
(c) nitrate ions
(d) nitrite ions
Short answer:
1. Certain amino acids function as precursors to other important nitrogen containing compounds. Match the amino acid on the right with the appropriate nitrogen containing compound on the left. An amino acid may be used more than once and if more than one amino acid serves as a precursor, you only need to give one. (15 points)
1. ethanolamine a. alanine
2. anserine b. glycine
3. gamma-amino butyric acid c. glutamic acid
4. creatine d. histidine
5. norepinephrine e. serine
6. thyroxine f. tyrosine
7. melatonin g. tryptophan
8. carnitine h. methionine
9. serotonin i. lysine
10. NAD(P) j. arginine
11. histamine k. ornithine
12. cadaverine
13. putrescine
14. spermine
15. glutathione
2. Indicate for each of the following amino acids if they are
glucogenic only (G), ketogenic only (K), or both glucogenic and
ketogenic (K & G). (10 points)
1. aspartic acid
2. glycine
3. cysteine
4. leucine
5. lysine
6. methionine
7. phenylalanine
8. histidine
9. threonine
10. isoleucine