75. Which of the following compounds is the substrate of ribonucleotide reductase?
(A) AMP
(B) TDP
(C) GTP
(D) CDP
(E) dAMP

71. Fatty acids are carboxylic acids with hydrocarbon chains ranging from ________ carbons long. (A) 12 to 24 (B) 4 to 36 (C) 6 to 24 (D) 6 to 36 (E) 12 to 32

72. The molecular weight of Protein A (pI = 4.0), B (pI = 6.8), and C (pI = 8.5) is 14 kDa, 24 kDa, and 30 kDa, respectively. All of them are monomer proteins. Which of the following statements is CORRECT? (A) Protein A elutes out first, when you use gel filtration column to separate the mixture of those three proteins. (B) Protein C is the one that moves fastest, when you separate the mixture of those three proteins by SDS-PAGE. (C) As shown in the right figure, you can use this isoelectric focusing apparatus to separate those three proteins. (D) When you use a DEAE ion exchange column and 10 mM Tris-Cl, pH 7.0 buffer to separate these three proteins, Protein A will be bound by this column. (E) None of the above

73. Which of the following is NOT related to RNA-RNA interaction? (A) guide RNA (B) Wobble (C) Shine-Dalgarno sequence (D) snRNA (E) None of the above

74. (1) Arg； (2) Asp； (3) Gly； (4) Cys； (5) His； (6) Ser； (7) Thr. Which of the followings does NOT appear in the preceding seven amino acid residues? (A) The amino acid residue in zinc finger to coordinate zinc atom (B) The amino acid residue in O-link glycoprotein to link protein and oligosaccharide (C) The amino acid residue in Type I topoisomerase to act as a nucleophile to cut DNA (D) The amino acid residue in terminal proteins of adenovirus to link nucleotides and protein (E) None of the above

76. (1) Ribozyme； (2) Okazaki fragment； (3) DNA polymerase needs an RNA primer but RNA polymerase doesn’t； (4) de novo biosynthesis of purine and pyrimidine； (5) retrovirus； (6) thermostable DNA polymerase. How many of the preceding items support the hypothesis that RNA appears before DNA? (A) 2 (B) 3 (C) 4 (D) 5 (E) 6

77. (1) release of acetyl-CoA； (2) release of CO2； (3) release of NADH. Pyruvate dehydrogenase can convert pyruvate into acetyl-CoA, NADH, and CO2. What is its reaction order of preceding three steps? (A) (1) → (2) → (3) (B) (1) → (3) → (2) (C) (2) → (1) → (3) (D) (2) → (3) → (1) (E) (3) → (1) → (2)

78. Xeroderma pigmentosum is caused by a defect in which DNA repair pathway. (A) Repair of oxidative damage (B) Daughter-strand gap repair (C) Base excision repair (D) Mismatch repair (E) Nucleotide excision repair

79. The reverse transcriptases possess the function of ① RNA-directed DNA polymerase activity ② Primase ③ DNA-directed DNA polymerase activity ④ RNase H activity ⑤ Helicase (A) ①②③ (B) ①②④ (C) ①②⑤ (D) ①③④ (E) ①③⑤

複選題80. Which of the following statements about the catabolism of free pyrimidines in the human body is CORRECT? ① Free cytosine and uracil are not salvaged ② Degradation of free cytosine produces β-alanine, CO2, and ③ Degradation of free uridine produces β-aminoisobutyric acid, CO2, and ④ Free thymine are recycled for synthesizing nucleosides (AB) ①②③ (AC) ①②④ (AD) ①② (AE) ①③ (BC) ①③④ (BD)一律送分

81. Which of the following statements about allosteric regulation is TRUE? (A) An allosteric inhibitor of an enzyme can be a competitive inhibitor. (B) An allosteric activator of an enzyme may reduce the apparent Vmax. (C) An allosteric activator cannot be substrate of allosteric enzymes. (D) An allosteric activator reduces the apparent Km. (E) An allosteric effector is a transition state analogue.