12. Joseph intended to donate his blood after a meal, but was found with a milky blood. Which plasma lipoprotein might be responsible for this phenomenon?
(A) Chylomicrons.
(B) VLDL.
(C) LDL.
(D) HDL.
(E) ACAT.

8. Iron deficiency in a cell can adversely affect electron transport at which of the following sites: (A) Cytochrome b and cytochrome c. (B) Coenzyme Q and FADH2. (C) NADH and FADH2. (D) Coenzyme Q and NADH. (E) All sites in electron transport are affected.

9. Which one of the following statements about glycolysis is     correct    : (A) Conversion of glucose to glyceraldehyde-3-phosphate is an exergonic reaction. (B) Conversion of glucose-6-phosphate to fructose-6-phosphate is a cleavage reaction. (C) Conversion of glyceraldehyde-3-phosphate to give 1,3-bisphosphoglycerate is a dehydration reaction. (D) Conversion of dihyroxyacetone phosphate to glyceraldehyde-3-phosphate is an isomerization reaction. (E) Conversion of 2-phosphoglycerate to give phosphoenolpyruvate is an oxidation reaction.

10. Which one of the following is     not     associated with the oxidation of substrates by the citric acid cycle? (A) CO2 production. (B) Pyridine nucleotide oxidation. (C) Flavin reduction. (D) Lipoic acid present in some of the enzyme systems. (E) All of the above are involved.

11. Which one is     not     related with cardiovascular disease? (A) Cholesterol. (B) Caveolin. (C) Avastin. (D) HMG-CoA reductase. (E) Lovastatin.

13. The compound that consists of deoxyribose linked by an N-glycosidic bond to N-1 of cytosine is: (A) a deoxyribonucleoside. (B) a purine nucleotide. (C) a pyrimidine nucleotide. (D) deoxycytidine monophosphate. (E) cytidine.

14. Deamination of the nucleotide base adenine yields nucleotide base: (A) xanthine. (B) inosine. (C) uracil. (D) hypoxanthine. (E) xanthylate.

15. The proportion of the human genome that is translated into protein is: (A) less than 0.5%. (B) roughly 1.5%. (C) roughly 10%. (D) roughly 15%. (E) roughly 25%.

16. The enzyme that catalyzes the conversion of GMP to GDP is: (A) nucleoside diphosphate kinase. (B) ribonucleotide reductase. (C) adenylate kinase. (D) guanine phosphoribosyltransferase. (E) nucleoside monophosphate kinase.

17. Which of the following descriptions about human hormones is     false    ? (A) Prostaglandins are examples of eicosanoid hormones. (B) The tropic hormones (such as thyrotropin, somatotropin, and luteinizing hormone) are produced and released by the anterior pituitary. (C) NO is derived from amino acid asparagine. (D) Eicosanoids are paracrine hormones. (E) Catecholamines are derived from amino acid tyrosine.

18. Which of the following descriptions is     false    ? (A) The double helix of DNA in the B-form is stabilized by nonspecific base-stacking interaction between two adjacent bases in the same strand. (B) The phosphodiester bond that joins adjacent nucleotides in DNA associates ionically with metal ions, polyamines, and proteins. (C) The phosphodiester bond that joins adjacent nucleotides in DNA is susceptible to alkaline hydrolysis. (D) The pentoses in nucleic acids do     not     undergo interconversion of the straight-chain form and the ring form. (E) The size and base composition of a double-stranded DNA are factors that affect the 'melting temperature of DNA.