87. How many of the following molecules act as second messengers?
GTP； calcium ion； cGMP； cAMP； inositol-1,4,5-triphosphate； diacylglycerol； ATP； insulin
(A) 8
(B) 7
(C) 6
(D) 5
(E) 4

83. Which statement about the chain elongation of vertebrate fatty acids is NOT true? (A) It occurs on the endoplasmic reticulum. (B) It utilizes malonyl-CoA as a substrate. (C) It elongates palmitoyl-CoA to stearoyl-CoA. (D) It gives a saturated fatty acyl-CoA two carbons longer than the original substrate. (E) It occurs in the cytoplasm.

84. P53 ______. (A) belongs to oncogene (B) regulates the activity of E2F transcription factor (C) cannot interact with DNA (D) repairs DNA damage directly (E) acts as a transcription factor to regulate cell cycle

85. Retinoid acid ______. (A) can be converted to retinal in the body (B) participates in the synthesis of β-carotene (C) combines with nuclear receptor that binds to specific DNA sequence (D) can replace vitamin A in the diet (E) acts as a chaperone at post-translational modification

86. What type of DNA will be formed if a DNA segment has one all-pyrimidine strand and one allpurine strand? (A) A-DNA formation (B) B-DNA formation (C) G-Quadruplexes (D) H-DNA formation (E) Z-DNA formation

88. Which of the following endogenous DNA-damaging reactions occurs most frequently in cells? (A) depurination (B) ROS oxidation (C) methylation (D) deamination (E) depyrimidination

89. How many pairs in the following are TRUE?- Iron-sulfur protein– electron flow from FMNH2 to coenzyme Q- Coenzyme Q – lipid soluble electron carrier- Cytochrome c – accepts electrons from complex IV- Flavin mononucleotide – accepts electron from NADH in complex - Q cycle – funnels electrons from a 2-electron carrier to a 1-electron carrier- Catalase – converts reactive oxygen species into hydrogen peroxide- Proton-motive force – hydrolysis of ATP (A) 3 (B) 4 (C) 5 (D) 6 (E) 7

90. The coupling oxidative phosphorylation means the joint of two reactions including① glucose + ATP → pyruvate + ADP + Pi② NADH + 1/2 O2 + H+ → H2O + NAD+③ ADP + Pi + H+ → ATP + H2O④ oxaloacetate + NADH → NAD+ + malate + H+ (A) ①③ (B) ②③ (C) ①④ (D) ②④ (E) ③④

1. Which unit is not the SI (international system of units) derived unit? (A) dyne (B) watt (C) newton (D) volt (E) tesla

2. Suppose a block is placed on a rough surface inclined relative to the horizontal and the coefficient of static friction between the block and the rough surface is μS. Let the incline angle be increased from θ = 0 until the block starts to move. What is the critical angle θc at which this slipping just occurs? (A) θc= arctan(μS )  (B)θc= arccos(μS )(C)θc=arcsin(μS ) (D)θc =π/2 (E) None of the above.

3. An escalator is used to move 20 people (60 kg each) per minute from the first floor of a department store to the second floor, 5 m above. The power required is approximately ______. (A) 100 W (B) 200 W (C) 1000 W (D) 2000 W (E) 4000 W