66. The high free energy change for the hydrolysis of a thiol ester, as found in acetyl-CoA, compared with that for the hydrolysis of a simple ester, is partly due to __________.
(A) the greater resonance stability in a simple ester due to better π-electron overlap in a CO linkage than in a CS linkage
(B) the gain in resonance energy in the product, acetate
(C) the high value for the bond energy in S-C bond
(D) reduction of the unfavorable electrostatic interaction in the acetyl-CoA
(E) the high value for the bond energy in S-P bond

62. Many coenzymes are derived from vitamins. Which of the following statements are correct? ① FAD is derived from vitamin B6. ② Pyridoxal phosphate is derived from vitamin B1. ③ Coenzyme A is derived from pantothenic acid. ④ 5’-Deoxyadenosyl cobalamin is derived from vitamin B12. ⑤ NAD is derived from nicotinic acid. (A) ①②③ (B) ②③④ (C) ③④⑤ (D) ①④⑤ (E) ①③⑤ 

63. Vitamin B1 (thiamine) is the precursor to the coenzyme thiamine pyrophosphate (TPP). Thiamine deficiency would decrease which one of the following enzyme activities? (A) Fumarase (B) Isocitrate dehydrogenase (C) Malate dehydrogenase (D) Succinate dehydrogenase (E) α-Ketoglutarate dehydrogenase

64. Which one of the representations describes the oligopeptide shown below? (A) Tyr-Ala-Thr (B) Tyr-Ala-Ser (C) Phe-Ala-Thr (D) Phe-Gly-Cys (E) Phe-Ala-Tyr

65. Which of the following statements regarding Michaelis-Menten kinetic analyses of enzyme action are correct? ① The total enzyme concentration studied at each substrate concentration is fixed in analysis of enzyme kinetics. ② Formation of enzyme-substrate complex does not appreciably decrease the concentration of substrate. ③ cat reduces with competitive inhibition. ④ Maximal velocity is reached when the enzyme-substrate complex is equal to the total concentration of enzyme present. ⑤ The initial reaction velocity should be measured because most of the substrate has not been converted to product. (A) ①②③④ (B) ①②③⑤ (C) ①②④⑤ (D) ②③④⑤ (E) ①③④⑤

67. Phosphate (Pi) is transported into the mitochondria from the cytosol by a phosphate carrier which is driven by the ____________. (A) hydrolysis of ATP (B) simultaneous transport of H+ into the mitochondrion (C) simultaneous transport of ADP into the mitochondrion (D) simultaneous transport of H+ out of the mitochondrion (E) simultaneous transport of ATP out of the mitochondrion

68. Which of the following statements regarding metabolism is NOT correct? (A) The metabolism can be classified as either catabolic or anabolic reactions. (B) Enzymes are usually required for cells to carry out reaction under condition of moderate temperature, pressure, and pH. (C) Glucose, fatty acids, and some amino acids are reduced to form acetyl-CoA, which enters the citric acid cycle. (D) The energy of metabolism is used to synthesize ATP from ADP and Pi. (E) Reactions occur spontaneously only when the free energy change is negative.

69. Which of the following statements about membrane proteins are correct? ① Membrane proteins can be extracted from cell membrane using sodium dodecyl sulfate. ② Integral proteins can span the membrane with α-helical structure or β-sheet structure. ③ Estrogen receptor is a membrane protein. ④ The membrane proteins are not associated with membrane through glycosylphosphatidylinositol anchor. ⑤ The transmembrane helix of membrane proteins can be predicted from hydropathic index of amino acid sequence. (A) ①②③ (B) ①②⑤ (C) ①②④ (D) ②④⑤ (E) ①③④

70. Which following post-translational modifications would NOT be found in histone? (A) Acetylation (B) ADP-ribosylation (C) Farnesylation (D) Methylation (E) Monoubiquitylation

71. In order to analyze transcription factor-DNA interaction in gene expression, the following experiments can be conducted. ① Promoter luciferase activity assay ② Electrophoretic mobility shift assay ③ Southern blotting ④ Chromatin immunoprecipitation ⑤ DNA affinity purification (A) ①③④⑤ (B) ①②③④ (C) ①②③⑤ (D) ①②④⑤ (E) ②③④⑤ 

72. Which of the following descriptions regarding DNA transcription is NOT correct? (A) DNA transcription is catalyzed by RNA polymerase consisting of a multi-subunit core and a σ factor. (B) The most common σ factor is  σ70 that binds at the promoter sequence. (C) The consensus sequence of the promoter includes a TATA box 10 base pairs upstream of the transcription start site. (D) Termination of RNA synthesis can be either rho-dependent or rho-independent. (E) RNA polymerase catalyzes mononucleotide transfer to the 5’-end.