所屬科目：研究所、轉學考(插大)◆生物化學
1. Which enzyme is used in gluconeogenesis, but NOT in glycolysis?(A) PEP carboxykinase(B) phosphohexose isomerase(C) enolase(D) 3-phosphoglycerate dehydrogenase
2. In allosteric interactions(A) proteins that consist of a single polypeptide chain form aggregate(B) disulfide bonds are broken(C) metal ions always bind to the protein(D) changes that take place in one site of a protein cause drastic changes at adistant site
3. The term “quaternary” with respect to protein structure means(A) a multisubunit structure.(B) the ability to form all four kinds of noncovalent bonds.(C) a linear sequence of four amino acids.(D) a repeating structure stabilized by intrachain hydrogen bonds.
4. The processing of one molecule of stearic acid (18 carbons) by β-oxidation(A) requires 9 cycles of β-oxidation and produces 8 molecules of acetyl-CoA(B) requires 9 cycles of β-oxidation and produces 9 molecules of acetyl-CoA(C) requires 8 cycles of β-oxidation and produces 9 molecules of acetyl-CoA(D) requires 8 cycles of β-oxidation and produces 8 molecules of acetyl-CoA
5. What charged group(s) are present in glycine at a pH of 7?(A) –NH3+ (B) –COO- (C) –NH2+ (D) A and B (E) A, B, and C
6. What is the Bohr effect?(A) the alteration of hemoglobin conformation during low oxygen(B) the regulation of hemoglobin-binding by hydrogen ions and carbon Dioxide(C) the ability of hemoglobin to retain oxygen when in competition withmyoglobin stress(D) all of the above
7. The protein myoglobin(A) contains no histidine(B) carries oxygen in the bloodstream(C) contains a heme group(D) contains a high degree of β-pleated sheet structure
8. Which of the following modifications is likely to happen to the mRNA in aeukaryotic cell?(A) removal of intervening sequences (introns)(B) capping of the 5' end(C) addition of a poly-A tail to the 3' end(D) All of the above occur in eukaryotic cells
9. Which of the following lipidsis not found in biological membranes?(A) phosphoacylglycerols(B) Triacylglycerols(C) cholesterol(D) glycolipids
10. Which of the following four fatty acids has the highest melting point?(A) CH3CH2CH2CH2CH2COOH(B) CH3 CH2CH2CH2CH2 CH2CH2CH2CH2COOH(C) CH3 CH2CH2CH2CH2 CH2CH2COOH(D) CH3CH=CHCH2CH2COOH
11. Which of the following best describes negative cooperativity?(A) Binding of one substrate molecule prevents the enzyme from working atall.(B) Binding of one substrate molecule inhibits the binding of a secondsubstrate.(C) Binding of one substrate molecule enhances the binding of a secondsubstrate.(D) Binding of one substrate molecule inhibits the binding of other effectors.
12. Two-dimensional electrophoresis is a combination of what two techniques?(A) isoelectric focusing and ion-exchange chromatography(B) isoelectric focusing and SDS-PAGE(C) ion-exchange chromatography and SDS-PAGE(D) affinity chromatography and SDS-PAGE
13. The degree of membrane fluidity depends on(A) the percentage of unsaturated fatty acids(B) the percentage of fatty acids(C) the percentage of lipids that contain choline(D) the percentage of glycolipids
14. Which of the following statements concerning messenger RNA is true?(A) It is the most abundant of the commonly occurring forms of RNA(B) It has extensive intrachain hydrogen bonding.(C) It turns over rapidly.(D) All of the above are true
15. Compared with DNA polymerase, reverse transcriptase(A) does not require a primer to initiate synthesis.(B) makes more errors because it lacks the 3' to 5' proofreading exonucleaseactivity.(C) introduces no errors into genetic material because it synthesizes RNA,not DNA.(D) synthesizes complementary strands in the opposite direction from 3' to 5'
16. An Okazaki fragment is a(A) piece of DNA that is synthesized in the 3' to 5' direction(B) fragment of RNA that is a subunit of the 30S ribosome.(C) fragment of DNA resulting from endonuclease action.(D) segment of DNA that is an intermediate in the synthesis of the laggingstrand.
17. Which of the following amino acids can be phosphorylated?(A) tyr, ser, thr(B) his, ser, phe(C) tyr, ser, trp(D) tyr, met, trp
18. The difference between active transport and passive transport is that(A) concentration gradients are involved in one and not in the other(B) glycolipids play a role in one and not in the other(C) one requires expenditure of energy by the cell and the other does not(D) ions are transported into and out of the cell by one process and not by theother
19. What is substrate level phosphorylation?(A) ATP and AMP synthesis from two molecules of ADP(B) Phosphorylation of AMP by ATP(C) Phosphorylation of ATP coupled to an ion gradient(D) ATP synthesis when the phosphate donor is a substrate with highphosphoryl transfer potential
20. The reactions of glycolysis occur in this eukaryotic cell compartment?(A) Mitochondrion(B) Nucleus(C) Cytoplasm(D) Both cytoplasm and mitochondria
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