47. Which of the following proteins have quaternary structure? I. Methionine II. Lysozyme III. Collagen IV. Hemoglobin
(A) I and II
(B) III and IV
(C) I, II, and IV
(D) II, III, and IV
(E) II and III

43. Which of the following statements about gene cloning is FALSE? (A) DNA with specific palindromic sequence can be cut by restriction enzymes. (B) EcoRI, a restriction enzyme from E. coli, cut DNA into sticky ends. (C) Gene of interest can be linked into plasmid with DNA polymerase. (D) The plasmids are transformed into competent cells. (E) Ions such as CaCl2 affect whether or not a bacterium will be competent cells.

44. Which of the following statements about neurotransmitter is FALSE? (A) Dopamine is derived from tyrosine and released by ventral tegmental area (VTA) neuron. (B) Epinephrine derived from tryptophan is important for fight-or-flight reactions. (C) Serotonin derived from tryptophan affect sleep and mood. (D) Endorphin is a neuropeptide to mediate pain perception. (E) Substance P is a neuropeptide to mediate pain perception.

45. Which of the following statements about drugs is FALSE? (A) Taxol inhibits cancer cells by preventing microtubule depolymerization. (B) Tamoxifen inhibits cancer cells by blocking the function of estrogen receptor. (C) RU486 induces abortion by blocking the function of estrogen receptor. (D) Erythromycin inhibits the growth of bacteria by blocking their ribosomes. (E) Chloramphenicol inhibits the growth of bacteria by blocking their ribosomes.

46. Which of the following sugars contain ketone group? (A) glyceraldehyde (B) ribose (C) glucose (D) fructose (E) galactose

48. Endomembrane system includes following organelles, except ______. (A) nuclear envelope (B) endoplasmic reticulum (ER) (C) Golgi apparatus (D) mitochondria (E) lysosome

49. Which of following is NOT a second messenger in signal transduction? (A) proton (B) cAMP (C) Ca2+ (D) inositol triphosphate (IP3) (E) diacylglycerol (DAG)

50. All of the enzymes catalyze reactions to produce NADH , FADH2 or ATP in citric acid cycle, except ______. (A) isocitrate dehydrogenase (B) α-ketoglutarate dehydrogenase (C) succinyl-CoA synthetase (D) succinate dehydrogenase (E) citrate synthetase

51. Which of the following molecule does NOT participate in oxidative phosphorylation? (A) proton (B) Ca2+ (C) ubiquinone (Q) (D) cytochrome c (cyt c) (E) ADP

52. Which of the following statements about cell cycle is FALSE? (A) Cyclin is degraded during G1. (B) Synthesis of cyclin begins in S phase. (C) Cyclin combines with Cdk to produce maturation-promoting factor (MPF). (D) MPF promotes mitosis by phosphorylating various proteins. (E) MPF’s activity peaks during prophase of M phase.

53. Which of the following statements about inherited disorders is FALSE? (A) Cystic fibrosis, a recessive disease, is caused by the defect of Cl- transporter. (B) Tay-Sachs disease, a dominate disease, is caused by the defect in mitochondria. (C) Phenylketonuria, a recessive disease, is caused by inability to metabolized phenylalanine. (D) Huntingon’s disease, a dominate disease, is a neuron degenerative disease. (E) Sickle-cell disease caused by T to A substitution results in defect of hemoglobin.