90. Which of the following posttranslational modifications is applied to produce active insulin
molecules in pancreatic β cells:
① Phosphorylation of Ser residues
② Glycosylation of Asn residues
③ Cleavage of a signal sequence
④ Proteolytic cleavage of internal sequences
⑤ Formation of disulfide bonds
(A) ③④⑤
(B) ②③④
(C) ②⑤
(D) ①②④⑤
(E) ①②③⑤

86. Which pair of enzymes is involved in glycolysis but NOT in gluconeogenesis? (A) Hexokinase and phosphohexose isomerase (B) Phosphofructokinase and pyruvate kinase (C) Phosphofructokinase and phosphoglycerate kinase (D) Phosphoglycerate kinase and pyruvate kinase (E) Phosphoglycerate mutase and enolase

87. Amino acids can be classified into different groups based on the R-group structure. Which class of amino acids contains only nonessential amino acids? (A) Hydrophobic (B) Aromatic (C) Polar, uncharged (D) Positively charged (E) Negatively charged

88. The functions of cholesterol include all the following except: (A) A precursor of bile (B) A precursor of vitamin D (C) As an intracellular energy source (D) Sustain cell membrane structure (E) Essential for producing steroid hormone

89. The following statements about lipid transport are all correct except: (A) Dietary triacylglycerols and cholesterol from intestine is carried by chylomicrons to muscle and adipose tissues. (B) VLDL carries triacylglycerols and cholesterol from liver to muscle and adipose tissues. (C) LDL carries mainly triacylglycerol from liver to muscle and adipose tissues. (D) HDL synthesized from liver picks up cholesterol in the bloodstream and transported back to liver. (E) The loss of triacylglycerols converts VLDL to LDL.

1.An object starts from rest at the origin and moves along the x axis with a constant acceleration of 4 m/s2. Its average velocity as it goes from x = 2 m to x = 8 m is: (A) 1 m/s (B)2m/s(C)3m/s (D) 5m/s (E) 6 m/s

2.A ball is thrown horizontally from the top of a 20-m high hill. It strikes the ground at an angle of ㆍ450. With what speed was it thrown? Use g = 10 m/s2.  (A) 14m/s (B) 20m/s (C) 28 m/s (D) 32 m/s(E) 40 m/s

3.The speed of a particle moving in a circle 2.0 m in radius increases at the constant rate of 6.0 m/s. At an instant when the magnitude of the total acceleration is 10.0 m/s, what is the speed of the particle?(A)3.0 m/s(B)4.0 m/s (C) 5.0 ml/s (D)6.0 m/s(E)8.0 m/s

4.Block A, with a mass of 10 kg, rests on a 30* incline. The coefficient of kinetic friction is 0.20. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. Block B, with a mass of 8.0 kg, is attached to the dangling end of the string (take √3 1.7 and g =10 m/s2). The acceleration of B is: (A) 0.72 m/s2, up (B) 0.72 m/s2, down (C) 2.6 m/s2, , up (D) 2.6 m/s2, down (E) 0 m/s2

5.Block A, with mass ma, is initially at rest on a horizontal floor. Block B, with mass mb, is initially at rest on the horizontal top surface of A. The coefficient of static friction between the two blocks is Hh- Block A is pulled with a horizontal force It begins to slide out from under B if the force is greater than: (A)mAg (B) mBg (C) u smig (D)usmBg (E)us(mA+mB)g

6.As a 2.0-kg object moves from m, the constant resultant force acting on it is equal to N. If the speed of the object at the initial position is 4.0 m/s, what is its kinetio energy at its final position? (A)62 J (B)53J (C)73J (D)86J (E)24 J