2012年7月生物化学作业答案（Answers to biochemical assignments in July 2012）The 1. antibiotic that inhibits protein biosynthesis in prokaryotes and prokaryotes is A. cycloheximideB. tetracyclineStreptomycin C.D. chloramphenicolPuromycin E.Full Score: 2 points2. amino acids are bound to tRNA by one of the following chemical bonds? A. glycosidic bondB. phosphate bondC. ester bondD. hydrogen bondE. amide bondFull Score: 2 pointsThe 3. transcription is the template of the A. previously derived strandB. takes two strands of DNA as templatesC. takes encoding chain as templateD. takes a chain of DNA as templateE. takes RNA as templateFull Score: 2 points4. in eukaryotic cells, the transcription product catalyzed by RNA polymerase II is A. 18SrRNAB. tRNAC. all RNAD. mRNAE. 28SrRNAFull Score: 2 pointsThe substance binding to CAP locus 5. is A. RNA polymeraseB. operonC. catabolite gene activator proteinD. repressor proteinE. cGMPFull Score: 2 points6. the essential amino acids in the following amino acids are A. glycineB. methionineC. tyrosineD. arginineE. histidineFull Score: 2 points7. the isoelectric point of protein is the pH value of A. when the protein is positively charged or negatively chargedPH value of B. solution when the pH value of protein solution is equal to 7C. protein molecules are facultative ions, and the pH value of solution is zero when the net charge is zeroPH value of solution in positive ion state of D. protein moleculePH value of solution when E. protein molecule is in negative ion stateFull Score: 2 points8. amino acid with two carboxyl groups is A. glycineB. tryptophanC. aspartic acidD. lysineE. serineFull Score: 2 points9. the starting point of eukaryotic biogenesis in protein biosynthesis is A. bright acyl tRNA tRNAB. alanine tRNAC. lysine tRNAD. fmet tRNAE. methionine tRNAFull Score: 2 points10. there is no A. lactone in red blood cells of patients with broad bean diseaseB. pentose phosphate isomeraseC. 6- glucose-6-phosphate dehydrogenaseD. transketolaseE. 6- glucose phosphate dehydrogenaseFull Score: 2 points11. when determining the enzyme activity, in the reaction system, the correct description is that the higher the concentration of A. isThe longer the incubation time of B., the betterThe reaction temperature of C. is better at 37D. pH must be neutralE. some enzymes need to add activatorsFull Score: 2 points12. glycolysis provides a pair of metabolites that P can produce ADP by ATP is A. 3- phosphate aldehyde and 6- fructose phosphateB. 1,3- - and phosphoenolpyruvateC. 3- and 6- phosphoglycerate glucose phosphateD. 1- glucose phosphate and phosphoenolpyruvate acidE. 1,6- and 1,3- - fructose diphosphateFull Score: 2 pointsThe 13. DNA replication system does not include A. CTPB. ATPC. dNTPD. DNA polymeraseE. DNA templateFull Score: 2 pointsThe rate limiting enzyme of 14. fatty acid beta oxidation is A. acyl CoA synthetaseB. carnitine acyl transferase IC. carnitine acyl transferase IID. acyl CoA dehydrogenaseE. beta keto acyl CoA sulfur lyaseFull Score: 2 points15. cAMP is involved in the transcriptional regulation of A. cAMP to CAPB. CAP transforms to cAMPC. cAMP and CAP form complexesD. glucose is active in decomposition, increasing cAMP, and promoting lactose utilization to expand energyE. cAMP is the second messenger of hormone action and has nothing to do with transcriptionFull Score: 2 points16. Okazaki fragment refers to the A. DNA template on discontinuous DNA fragmentDiscontinuous DNA fragments generated on B. follower chainsDiscontinuous DNA fragments generated on C. preamble chainSynthesis of RNA fragments catalyzed by D. primersDNA fragment of E. synthesized by DNA ligaseFull Score: 2 points17. the energy sources in the brain and muscle cells are A. blood sugar in normal physiological conditionsB. fatty acidC. ketone bodiesD. amino acidE. nucleotide AFull Score: 2 points18. does the activated G protein directly affect the following enzymes? A. protein kinase AB. protein kinase CC. protein kinase GD. phospholipase AE. phospholipase CFull Score: 2 points19. the right thing about corruption is that A. is the gut bacteriums effect on protein or protein digestionB. is the main decomposition of amino acid decarboxylation, deamination.C. is mainly carried out in the large intestineD. is responsible for all the harmful substances produced by putrefactionE. is the metabolic process of bacteria itself, mainly by aerobic decompositionFull Score: 2 points20. the A. promoter is the positive regulator in eukaryotic gene transcriptionB. operon