BIOCHEMISTRY 4613/6613

Exam 4 - April 7, 2000

Row number: Name:

SHORT ANSWER:

1. Which of the following fatty acids is considered to be essential for most if not all animals? (3 points).

a. oleate

b. linoleate

c. arachidonate

2. Prostaglandins are synthesized from: (3 points)

a. arachidonic acid

b. linolenic acid

c. cholesterol

3. Cholesterol is synthesized from: (3 points)

a. acetyl CoA

b. malonyl CoA

c. acetyl CoA and malonyl CoA

4. Phosphatidic acid is NOT an intermediate in the synthesis of: (3 points)

a. triacylglycerols

b. phospholipids

c. cholesterol

5. Which of the following plasma lipoproteins contain the largest amount of total cholesterol? (3 points)

a. VLDL

b. LDL

c. HDL

Reactions: Give the name of the substrate(s), product(s) and coenzyme(s) for each of the following enzymes. No structures necessary.

6. Aspartate aminotransferase (10 points)

7. Glutamic dehydrogenase (8 points)

8. Glutamine synthetase (8 points)

9. Illustrate using name reactions only the glucose-alanine cycle. (15 points)

10. Illustrate using name reactions only the urea cycle. Use ammonia as the starting material and give the name of the enzyme involved for each step. (15 points)

Matching:

11. 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. (10 points)

Ethanolamine                                   a. alanine

Anserine                                          b. glutamic acid

Gamma-amino butyric acid              c. histidine

Norepinephrine                               d. serine

Thyroxine                                        e. tyrosine

Melatonin                                        f. tryptophan

Carnitine                                         g. methionine

Serotonin                                        h. lysine

Cadaverine                                     i. arginine

Putrescine                                       j. ornithine

12. Indicate for each of the following amino acids if they are glucogenic only (G), ketogenic only (K), or glucogenic and ketogenic (G & K). (9 points)

Aspartic acid

Histidine

Isoleucine

Leucine

Lysine

Methionine

Phenylalanine

Threonine

Tryptophan

Short Answer:

13. Name the 10 amino acids which are considered to be essential for most if not all young rapidly growing animals. (10 points)