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

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

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

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.

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.

73. Which of the following statements regarding lipids is NOT correct? (A) Lipids are usually water soluble. (B) Fatty acids are relatively long-chain monocarboxylic acids with even carbon numbers ranging from 12 to 20. (C) Fatty acids are generally stored as complex lipids called triacylglycerols. (D) Glycerophospholipids are the major amphipathic lipid components of biological membranes. (E) Cis-form unsaturated fatty acids can change the membrane fluidity a lot.

74. Which of the following statements regarding lipid metabolism is NOT correct? (A) The degradation pathway consists of oxidation, hydration, further oxidation, and thiolysis. (B) Before that, fatty acids are activated by esterification to coenzyme A. (C) Fatty acid degradation produces large amounts of ATP. (D) Fatty acids are degraded to acetyl-CoA by the sequential removal of two-carbon fragments, a process called α-oxidation. (E) Fatty acids are usually synthesized from the acetyl-CoA.

75. Which of the followings is on the surface of a lipoprotein particle? (A) Cholesterol and phospholipids (B) Cholesterol and triacylglycerol (C) Cholesteryl ester and triacylglycerol (D) Cholesteryl ester and phospholipids (E) Triacylglycerol and phospholipids