生物化学英文版习题文档格式.docx
《生物化学英文版习题文档格式.docx》由会员分享,可在线阅读,更多相关《生物化学英文版习题文档格式.docx(61页珍藏版)》请在冰豆网上搜索。
Asp-Ala-Ser-Glu-Val-Arg
9.TheC-terminalaminoacidofthehexapeptideshownis
(A)alanine(B)asparagine(C)aspartate(D)arginine
10.AtphysiologicpH(7.4),thishexapeptidewillcontainanetchargeof
(A)-2(B)-1(C)0(D)+1(E)+2
11.Whichoneofthefollowingtypesofbondsiscovalent?
(A)Hydrophobic(B)Hydrogen(C)Disulfide(D)Electrostatic
13.Whichoneofthefollowingconditionscauseshemoglobintoreleaseoxygenmore
readily?
(A)Metabolicalkalosis
(B)Increasedproductionof2,3-bisphosphoglycerate(BPG)
(C)Hyperventilation,leadingtodecreasedlevelsofCO2intheblood
(D)Replacementoftheβsubunitswithγsubunits
14.Productionofwhichofthefollowingproreinswouldbemostdirectlyaffectedin
scurvy?
(A)Myoglobin(B)Collagen(C)Insulin(D)Hemoglobin
15.Theactivesiteofanenzyme
(A)isformedonlyafteradditionofaspecificsubstrate
(B)isdirectlyinvolvedinbindingofallostericinhibitors
(C)residesinafewadjacentaminoacidresiduesintheprimarysequenceofthe
polypeptidechain
(D)bindscompetitiveinhibitors
16.AnenzymecatalyzingthereactionE+S=ES→E+Pwasmixedwith4mMsubstrate.Theinitialrateofproductformationwas25%ofVm.TheKmfortheenzymeis
(A)2mM(B)4mM(C)9mM(D)12mM(E)25mM
17.Thevelocity(v)ofanenzyme-catalyzedreaction
(A)decreasesasthesubstrateconcentrationincreases
(B)islowestwhentheenzymeissaturatedwithsubstrate
(C)isrelatedtothesubstrateconcentrationatlhVm
(D)isindependentofthepHofthesolution
Questions18and19
Refertothefollowingreactionwhenansweringquestions18and19.
Fumarate+H20↔malate
fumarase
18.Fumarasecatalyzestheconversionoffumaratetomalate.IthasaKmof5μMfor
fumarateandaVmaxof50μmol/min/mgofproteinwhenmeasuredinthedirectionofmalateformation.Theconcentrationoffumaraterequiredtogiveavelocityof25μmol/min/mgproteinis
(A)2μM(B)5μM(C)10μM(D)20μM(E)50μM
19.TheKmforfumaraseisapproximately5μMforfumarate.Thefumarateconcentrationinmitochondriaisapproximately2mM.Ifthefumarateconcentrationdroppedto1mM,thereactionratewould
(A)increaseslightly(B)decreaseslightly
(C)decreasebyonehalf(D)stayexactlythesame
20.Hexokinaseandglucokinasebothcatalyzethephosphorylationofglucosetoglucose6-phosphate.ThevaluesofKmfortheenzymesare10μMand0.02M,respectively.Ifbloodglucoseis5mMunderfastingconditionsand20mMafterahigh-carbohydratemeal
(A)hexokinasewillfunctionnearitsVmaxunderfastingconditions
(B)glucokinasewillfunctionnearitsVmaxunderfastingconditions
(C)hexokinasewillfunctionatlessthanone-halfVmaxafterahigh-carbohydratemeal
(D)glucokinasewillfunctionatlessthanone-halfVmaxafterahigh-carbohydratemeal
21.Acompetitiveinhibitorofanenzyme
(A)increasesKmbutdoesnotaffectVmax
(B)decreasesKmbutdoesnotaffectVmax
(C)increasesVmaxbutdoesnotaffectKm
(D)decreasesVmaxbutdoesnotaffectKm
(E)decreasesbothVmaxandKm
Questions22-25
Refertothegraphwhenansweringquestions22-25.
22.ThevalueofKmfortheenzymedepictedbycurveAis
(A)0.5mM(B)1mM(C)2mM(D)1μmol/min/mg(E)10μmol/min/mg
23.ThevalueofVmfortheenzymedepictedbycurveAis
(A)0.1μmol/min/mg(B)1μmol/min/mg
(C)10μmol/min/mg(D)0.5mM(E)2mM
24.CurveBdepictstheeffectofaninhibitoronthesystemdescribedbycurveA.Thisinhibitor
(A)isacompetitiveinhibitor(B)isanoncompetitiveinhibitor
(C)increasestheVmax(D)decreasestheKm
25.CurveCdepictstheeffectofadifferentinhibitorofthesystemdescribedbycurveA.Thissecondinhibitor
(A)isacompetitiveinhibitor
(B)isanoncompetitiveinhibitor
(C)increasestheVmax
(D)decreasestheKm
answer:
DBCBBDDCBBAAACAB
Eachgroupofitemsinthissectionconsistsofletteredoptionsfollowedbyasetofnumbereditems.Foreachitem,selecttheoneletteredoptionthatismostcloselyassociatedwithit.Eachletteredoptionmaybeselectedonce,morethanonce,ornotatall.
Questions33-37
Matcheachcharacteristicbelowwiththeproteinitbestdescribes.
(A)Hemoglobin(B)Myoglobin(C)Collagen(D)Insulin
33.RequiresvitaminCforitssynthesis
34.Hasoneoxygenbindingsiteandonepolypeptidechain
35.Containsfourmoleculesofheinepermolecule