15. The enzyme glycogen phosphorylase:
(A) catalyzes a cleavage of β(1→4) bonds.
(B) catalyzes a hydrolytic cleavage of α(1→4) bonds.
(C) is a substrate for a kinase.
(D) uses glucose 6-phosphate as a substrate.
(E) uses glucose as a substrate.

11. Which statement is correct?(A) The biosynthesis of dNTPs uses NTPs as the source.(B) The overall scheme of pyrimidine biosynthesis is the same as purine.(C) The pyrimidine catabolism is first degraded to the nucleobase.(D) The pyrimidine ring is assembled before it is attached to ribose-5-phosphate.(E) Ribonucleotide reductase catalyzes deoxyribose to ribose in all biology.

12. Glutamate is metabolically converted to a-ketoglutarate and NH4+ by a process described as:(A) reductive deamination. (B) hydrolysis. (C) transamination.(D) deamination. (E) oxidative deamination.

13. In phosphory1 group transfer reactions, the____of the nucleotide serves as an information symbol, channeling  the nucleotide to appropriate metabolic activities.(A) sugar (B) diphosphate anhydride (C) sugar-phosphate ester(D) base (E) None are true.

14. Which of the following statements about mitochondrial transport systems is correct?(A) Malate-aspartate shuttle: converts cytosolic NADH to mitochondrial FADH2(B) ATP-ADP translocase: transfers ATP and a proton from matrix to cytosol while transferring ADP from cytosol to matrix(C) Glycerophosphate shuttle: converts cytosolic FADH2 to mitochondrial NADH(D) The malate-aspartate shuttle is irreversible while the glycerophosphate shuttle is reversible.(E) None of the above are correct.

16. All are characteristics associated with "brown fat" except:(A) high levels of mitochondria rich in cytochromes.(B) presence of uncoupler protein-1, thermogenin, in the mitochondrial inner membrane.(C) energy from oxidation is converted to heat.(D) found in newborns and hibernating animals.(E) All are characteristics.

17. From the abbreviated name of the compound Gal(β1→4)Glc, we know that:(A) C-4 of glucose is joined to C-1 of galactose by a glycosidic bond.(B) the compound is a D-enantiomer.(C) the galactose residue is at the reducing end.(D) the glucose is in its pyranose form.(E) the glucose residue is the β anomer.

18. When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the enzyme phosphohexose isomerase, the final mixture contains twice as much giucose 6-phosphate as fructose 6-phosphate. Which one of the following statements is most nearly correct, when applied to the reaction below? (R = 8.315 J/mol·K 且 T = 298 K) Glucose 6-phosphatefructose 6-phosphate(A)  ΔG'° is +1.7 kJ/mol. (B)  ΔG'° is -1.7 kJ/mol.(C) ΔG'° is incalculably large and negative.(D) ΔG'°is incalculably large and positive. (E)  ΔG'° is zero.

19.If carbon I is the carbony1 group of an aldopentose, which carbon determines if the sugar is a p- or L- stereoisomer?(A) 1 (B)2 (C) 3 (D) 4 (E) 5

20. In glycoproteins, the carbohydrate moiety is always attached through the amino acid residues:(A)asparagine, serine, or threonine. (B) aspartate or glutamate. (C) glutamine or arginine.(D) glycine, alanine, or aspartate. (E) tryptophan, aspartate, or cysteine.

21. Bacteria and other prokaryotic cells have the capacity to get more ATP/glucose oxidized than eukaryotic cells because__________，so they are more efficient.(A) they are simpler and have less going on(B) they don't have to use shuttles to reoxidize reduced nucleotides(C) they do not have to translocate ATP-ADP across the mitochondrial membranes(D) they use an electron transport chain that translocates more protons(E) None of the above.