84. Which of the following is a ribonucleoprotein required for the delivery of membrane and secretory proteins to the endoplasmic reticulum?
(A) small ubiquitin-related modifier (SUMO)
(B) signal recognition particles (SRP)
(C) trigger factor
(D) protein-conducting channel (PCC)
(E) calnexin

80. Which of the following statements regarding biosynthesis of fatty acids is correct? (A) NADH is required in the biosynthesis of fatty acids. (B) Fatty acids synthase I in vertebrates consists of 4 polypeptide chains. (C) Fatty acids synthase I is not a homodimer molecule. (D) HCO3 - is involved in biosynthesis of fatty acids. (E) There are 8 active sites in fatty acids synthase I.

81. Which of the following statements about Klenow fragment is false? (A) Klenow fragment is derived from E. coli DNA polymerase I. (B) It contains DNA polymerase activity. (C) It contains 3’→5’ exonuclease activity. (D) Klenow fragment is derived from large fragment of E. coli RNA polymerase I. (E) It is lack of 5’→3’ exonuclease activity.

82. Which of the following statements regarding β-oxidation of fatty acids is correct? (A) 16 acetyl-CoA molecules are produced by β-oxidation of palmitate. (B) One acetyl group is removed in one turn of β-oxidation. (C) In β-oxidation, ATP can be produced. (D) CO2 is generated by β-oxidation of palmitate. (E) The β-oxidation of unsaturated fatty acids has 4 basic steps.

83. Chartgraff's rules for DNA state that: (A) G+C = 39-46% in mammals (B) A=T and G=C (C) the sense strand is a right-handed helix (D) A=U and G=C (E) the minor groove is shallower than the major groove

85. Transcriptional activators that have variable positions and orientations are called _______. (A) enhancers (B) operators (C) introns (D) polycistrons (E) promoters

86. The peptide QYDG has a N-terminal _______ residue. (A) glutamic acid (B) glycine (C) glutamine (D) aspartic acid (E) alanine 

87. The reaction below is catalyzed by yeast alcohol dehydrogenase. Which of the following corresponds to X and Y? (A) X = NAD + H+ Y = NADH+ (B) X = NADH + H+ Y = NAD+ (C) X = NADPH + H+ Y = NADP+ (D) X = NAD+ Y = NADH + H+ (E) X = NADH+ Y =NAD + H+

88. In E. coli, base-pairing between a mRNA's ______ and the 3' end of the 16S rRNA permits the ribosome to select the proper initiation codon. (A) 5' cap (B) Shine–Dalgarno sequence (C) polyA tail (D) start codon (E) initiation factor

89. Chymotrypsin, a serine protease, preferentially cleaves a peptide bond adjoining a bulky non-polar side chain. This is because chymotrypsin's specificity pocket _______. (A) is mostly filled with large side chains (B) contains a negative charge (C) contains a positive charge (D) contains a sulfhydryl group that forms a disulfide bond with the substrate (E) is lined with small hydrophobic side chains, leaving considerable room in the nonpolar pocket

90. Oseltamivir (marketed as Tamiflu) has a structure mimicking ______, and thus is a strong inhibitor of neuraminidase of H1N1 influenza virus. (A) sialic acid (B) hyaluronic acid (C) sucrose (D) chondroitin sulfate (E) lactose