90. The coupling oxidative phosphorylation means the joint of two reactions including

① glucose + ATP → pyruvate + ADP + Pi

② NADH + 1/2 O₂ + H+ → H₂O + NAD⁺

③ ADP + P_i + H⁺ → ATP + H₂O

④ oxaloacetate + NADH → NAD⁺ + malate + H⁺
(A) ①③
(B) ②③
(C) ①④
(D) ②④
(E) ③④

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

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

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

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

4. An air-bag company is designing a new product. The specification requires passengers of mass 75 kg to sit in a car traveling at 60 km/h. When the car hits the wall and stops there, the air-bag extends the stopping time up to 0.4 s. What is the average force on the passenger during this collision? (A) 408 N (B) 1680 N (C) 3125 N (D) 11259 N (E) 30625 N

5. The electric inductance L is defined as the magnetic flux ΦB divided by current I. What is the unit of the inductance L divided by electric resistance R ? (A) tesla (B) Hz (C) Wb (D) sec (E) None of the above.

6. A hydraulic press has one piston of diameter 2 cm and the other piston of diameter 8 cm. What force must be applied to the smaller piston to obtain a force of 1600 N at the larger piston? (A) 6 N (B) 25 N (C) 100 N (D) 400 N (E) 1600 N