生化本科-试卷及答案

生化本科-A 卷及答案（留学生） 2012-2013学年第一学期《Biochemistry and molecular biology 》课程考试卷（A 卷）专业：Clinical medicine 层次：undergraduate course 年级：2011（total points ：100分，test time ：120mins ，试题内容5页，空白纸4页）The department director ：Objective questions:一、Single choice questions （1 point each,total 33points. Directions: Each of the questions below is followed by five suggested answers or completions. Select the one that is best in each case and then completely fill in the corresponding space on the answer sheet.）1、 Which pair of amino acids absorbs themost UV light at 280 nm? A, Thr & His.B, Trp & Tyr.C, Cys & Asp.D, Phe & Pro. E, None of the above. 2、 The deficiency of which one leads to Beriberi. A. vitamin B1 B. vitamin PP C. vitamin B2 D. vitamin E E. folic acid 3、 Holoenzyme refers to A. complex of enzyme and substrate B. complex of enzyme and inhibitor C. complex of apoenzyme and cofactor D. inactive precursors of enzyme E. complex of enzyme and allosteric effector 4、 Competitive inhibitor competes with the substrate molecules for binding to the A. ES complex B. a site other than the active site C. active site of the enzyme D. substrate E. subunit5、 directly participate in the making and breaking of bonds, catalyzing substrate to products.A. binding groupsB. catalytic groupsC. alkaline groupsD. acidic groupsE. hydrophobic groups 6、 Which of the following statements about the salvage pathway for the synthesis of purine nucleotides is correct? A.Increased PRPP levels in cells inactivate hypoxanthine-guanine phosphoribosyl transferase (HGPRT). B 、Decreased PRPP levels in cells lead to the activation of hypoxanthine-guanine phosphoribosyl transferase (HGPRT). C 、Increased PRPP levels in cells lead to the activation of hypoxanthine-guanine phosphoribosyl transferase (HGPRT). D 、Purine nucleotides competitivelyinhibit hypoxanthine-guanine phosphoribosyl transferase (HGPRT). E 、Salvage pathway is the major way to synthesize purine nucleotides in all tissue姓名：＿＿＿＿＿＿ 年级： 专业： 班别： 学号:□□□□□□□□□□7、Which of the following statements aboutthe de novo synthesis of purinenucleotides is correct?A、AMP is the first purine nucleotide assembled from the de novo pathway.B、The enzyme PRPP amidotransferase catalyses the committed step of the de novo synthesis pathway.C、IMP is a competitive inhibitor of PRPP synthetase.D、AMP is a competitive inhibitor of PRPP amidotransferase.E、GMP is the first purine nucleotideassembled from the de novo pathway.8、An RNA-dependent RNA polymerase islikely to be present in the virion of aA DNA virus that multiplies in the cytoplasmB DNA virus that multiplies in the nucleusC minus-strand RNA virusD plus-strand RNA virusE transforming virus9、Eukaryotic cells with DNA damage oftencease progression through the cell cycleuntil the damageis repaired. This type ofcontrol over the cell cycle is referred toasA proteosome controlB damage controlC checkpoint controlD anticyclin control10、Consider the average in vivo turnoverrates for proteins,DNA, and mRNA.Which of the following orders bestdescribes the turnover rate from fastest(shortest average lifetime) to slowest(longest average lifetime)?A mRNA > DNA > proteinsB mRNA > proteins > DNAC Proteins > mRNA > DNAD Proteins > DNA > mRNAEDNA > mRNA > proteins11、Which one is most unstable below: A．DNA double strand B．RNA hairpin C．C/G D．A/T E．A/U12、The principal site of peptideneurohormone biosynthesis is the AnucleusB rough endoplasmic reticulumC dendriteD postsynaptic densityE synaptic vesicle13、The K m (Michaelis constant) of anenzyme for a substrate is definedoperationally asA half the substrate concentration at which the reaction rate is maximalB the substrate concentration at which the reaction rate is half maximalC the dissociation constant of the enzymesubstrate complexD the dissociation constant of the enzymeproduct complexE the rate constant of the reaction at saturation14、Which of the following types ofmolecules is always found in virions?A LipidB ProteinC CarbohydrateD DNAE NA15、If the sense sequence is5'-ACTACTCAG3'，the complementarymRNA should be :A．5'-TGATCAGTC-3'B．5'-UGAUGAGUC-3'C．5'-CUGAGUAGU-3'D．5'-CTGAGTAGT-3'E．5'-CAGCUGACU-3'16、RNA synthetized by Eukaryotic RNApolymarase Ⅱ is：A．rRNA B.hnRNA C.tRNAD.5SRNAE.18SRNA17、DNA dependent RNA polymarase iscomposed of several subunits. The coreenzyme is：A. ααββ'B. ααββ'σC. ααβ'D. ααβE. αββ'18、The enzyme for transcription is ：A. DNA dependent RNA polymarase （DDRP）B.RNA dependent DNA polymarase （RDDP）C.DNA dependent DNA polymarase （DDDP）D.RNA dependent RNA polymarase （RDRP）E.Primase19、Which one below can transfer DNAgenetic information to protein?A. tRNA B．mRNA C. rRNA D．hnRAN E．AA20、The stop codon are :A．AUG AGU AGG B．UAG UGA UAA C．AUG AGU AUUD．UAG UGA UGG E．GAU GUA GAA 21、The sedimentation coefficient of theeukaryotic ribosome is:A. 40S + 60S=80S B．30S +50S=80S C. 40S + 60S=100S D．30S + 50S=70S E 50S + 20S=70S22、The main antioxidation in red blood cellsis:A. GSHB. NAD+C. NADP+D. FADE. FMN23、The secondary structure is a regularlyrepeating structure such as:A. Collagen helixB. Disulfide bondC. -helixD. DomainsE. All of the above24、Aspartic acid is similar to glutamic acidin the same way thatA. His is similar to PrB. Ser is similar to Cys.C. Gln is similar to AsnD. Asn is similar to Gln.E. Gly is similar to Val.25、Amino acids in protein belonging towhich of following? A. L-β-amino acidsB. D-β-amino acidsC. L-α-amino acidsD. D-α-amino acidsE. L,D-α-amino acids26、Nucleic acids generally doesn't contain（）A .carbonB .hydrogenC. sulfurD. oxygenE .nitrogen27、The RNA complementary strand ofDNA5’-CGGTA-3’ is:A．5’-GCCTA-3’B．5’-GCCAU-3’C．5’-UACCG-3’D．5’-TAGGC-3’E．5’-TUCCG-3’28、The Cori cycle describes the release oflactate from active muscle into thebloodstream and its subsequent uptakeby the liver. The lactate in the liver isthen used for:A. Glycogen synthesisB. ATP phosphorylationC. Phosphocreatine synthesisD. Glucose synthesisE. Alanine synthesis29、In a eukaryotic cell, most of the enzymesof the electron transport chain are locatedin theA. CytosolB. outer mitochondrial membrane.C. intermembrane space.D. inner mitochondrial membrane.E. mitochondrial matrix.30.Oxidation of palmitic acid (C16) involves ___ rounds of β-oxidation and yields ___ molecules of acetyl-CoA.A. 8, 8B. 7, 8C. 16, 8D. 7, 7E. 16, 731.Ras proto-oncogene is converted into oncogene byA. A point mutationB. Chromosomal translocationC. Insertion of a viral promoter upstream of the geneD. Gene amplificationE. Gene deletion32.Retinoblastoma can result from a mutation inA. Ras proto-oncogeneB. erbB proto-oncogeneC. p53 geneD RB geneE. c-myc gene 33.The only correct statement about oncoviruses isA. All the oncoviruses are RNA virusesB. Reverse transcriptase is present in all oncovirusesC. All the oncoviruses are DNA virusesD. Viral oncogenes are identical to human proto-oncogenesE. Both DNA and RNA can be oncoviruses二、Multiple choice questions（1 point each,total 3points）34.The most common structural feature of the DNA binding domain includes:A. helix-turn-helix motifB. zinc finger motifC. leucine zipper motifD. nucleolusE. cytoplasm35.Protein secondary structure including ( ) A.α-helix B.random coilC.β-pleated cheetD.β-turnE.subunit36.Antimetabolites of nucleotides include：A、Folic acid analogsB、Purine analogsC、Amino acid analogsD、Nucleoside analogsE、Pyrimidine analogsSubjective questions一、1. Domain2. HDL3、HMG-CoA reductase4、G-protein5、DNA replication6、codon二、brief answers（6 points each,total 24 ）1.What is the primary structure of protein? What kind of bond hold the structure?2、Please tell the DNA double helix model3、Why the liver can supple blood glucose?4.What are included in the Protein Synthetic System?三、essay questions（11 points each,total 22）5、What is beta-oxidation? What is the key enzyme? Please calculate how many NADH, FADH2 and acetyl-CoA will be generated by a 16 carbon fatty acid after comply oxidize by beta-oxidation.6. Which mechanism can ensure the Fidelity of DNA replication?《Biochemistry and molecular biology》课程考试卷（A卷）专业：Clinical medicine层次：undergraduate course年级：2011（total points：100分，test time：120mins）Objective questions:一、Single choice questions（1 point each,total 33points. Directions:Each of the questions below is followed by five suggested answers or completions. Select the one that is best in each case and then completely fill in the corresponding space on the answer sheet1.B2.A3.C4.C5.B6.C7.B8.C9.C 10.B 11.E 12B 13 B 14.B 15.C 16.B17.A 18 A 19 B 20 B 21 A 22A 23 C 24 D 25 C 26 C 27 C 28 D 29 D 30B 31 A 32D 33E 34 ABC 35ABCDE 36ABCDE二、Explanation of Terms（3points each,total 18 points）1.Subunit在四级结构的蛋白质分子中含有二条或二条以上的多肽链，其中每条都具有完整的三级结构，称为蛋白质的亚基。