醫(yī)學(xué)生物化學(xué)與分子生物學(xué)（17版）-成人教育學(xué)習(xí)通超星期末考試章節(jié)答案2024年ThesitetowhichRNApolymerasebindsontheDNAtemplatepriortotheinitiationoftranscription.

答案:PromoterAll

of

the

following

are

true

of

RNA

polymerase

except:

答案:ItbindstomostregionsofDNA.Small

snRNPs

are

involved

in:

答案:mRNAprocessingAmanwithabacterialinfectionwasprescribedrifampintoresolvetheinfection.Rifampindoesnotaffecteukaryoticcellduetowhichofthefollowing?

答案:StructurealdifferencesinRNApolymerasebetweeneukaryotesandprokaryotesTelomerase

contains

a

ribozyme.

答案:Telomeraseaddsarepeatingsequencetothe5'endofDNASingle-strandedbindingproteins(SSB)bindtotheouterbackboneofDNAduringreplication.WhatwouldyoupredictaboutSSBs?

答案:Theycontainarginineandlysineresidues.Why

does

lagging

strand

synthesis

consist

of

discontinuous

Okazaki

fragments?

答案:DNAissynthesized5'to3'.ReplicationcanonlyproceedfromtheunwoundportionofDNAoutward.DNA

replication

is

semiconservative.

Why

do

you

think

this

is

true?

答案:IncreasedfidelityDNA

replication

results

in:

答案:TwonewdaughterstrandsA2-year-oldchildpresentswithpoorweightgain,sparsehair,unusualfacewithsunkeneyes,andskinthatreddensmarkedlyinsunlight.AdiagnosisofCockaynesyndrome(MIM*216400)isconsideredandstudiesofDNAsynthesisareundertaken.InvitroassayoflabeledthymidineincorporationrevealsdecreasedlevelsofDNAsynthesiscomparedtocontrols,butnormal-sizedlabeledDNAfragments.TheadditionofproteinextractfromnormalcellsgentlyheatedtoinactivateDNApolymeraserestoresDNAsynthesisinCockaynecellstonormal.WhichofthefollowingenzymesusedinDNAreplicationismostlikelytobedefectiveinCockaynesyndrome?

答案:Unwindingproteinswhymammaliangenomesare100timesthesizeofbacterialgenomesyetarereplicatedinjustafewminutes.Whichofthefollowingbestexplainsthisfact?

答案:HundredsofreplicationforksworksimultaneouslyoneachpieceofmammaliangenomicDNAWhichofthefollowingisthedirectdonorofCH3?

答案:SAMWhich

of

the

following

is

the

process

that

transport

ammonia

from

muscle

to

liver?

答案:alanine-glucosecycleThe

transportation

form

of

ammonia

in

blood

is

答案:GlutamineThe

major

fate

of

ammonia

is

(

)

in

the

body.

答案:tosynthesizeureaIn

the

presence

of

hyperammonia,

production

of

which

of

the

following

amino

acids

is

always

increased?

答案:GlutamineWhich

of

the

following

amino

acid

can

produce

PAPS?

答案:cysteineWhichofthefollowingstateispositivenitrogenbalance?

答案:pregnantwomenWhichofthefollowingaminoacidcannotproduceonecarbonunit?

答案:ValineThecompoundwhichdoesnotbelongtoonecarbonunitasfollowis.

答案:CO2Whichoneofthefollowingaminoacidsisessentialinthehumandiet?

答案:LysineWhich

of

the

following

is

the

carrier

of

one

carbon

unit

?

答案:FH4Which

of

the

following

is

the

main

deamination

style

in

the

body?

答案:uniondeaminationWhich

of

the

following

is

not

produced

by

Tyr?

答案:PheWhichofthefollowingstateisnitrogenequilibrium?

答案:normaladultWhich

of

the

following

amino

acids

can

be

converted

into

taurine

in

the

body?

答案:CysteineWhichofthefollowingarethenitrogensourceofurea?

答案:carbomoylphosphateandaspartateMrSmithhadbeenprescribedadrugtotreathisdepression.Oneoftheeffectsofthedrugistomaintainelevatedlevelsofaparticularneurotransmitterthathasbeenderivedfromwhichofthefollowingaminoacids?

答案:TryptophanWhencomparedtohisstateafteranovernightfast,apersonwhofastsfor1weekwillhave

答案:lessmuscleproteinThemostimportantroleofS-adenosylmethionine(SAM)is.

答案:tosupplymethylgroupThe

primary

manner

for

the

deamination

of

amino

acids

in

muscle

involves.

答案:purinenucleotidecycleInhumans,obesityisnotcausedbyleptinlevels,butbymalfunctioningsignalmechanisms.Whichofthefollowingdoyouthinkmightbeaffectedbyhighleptinconcentrationsbindingtoreceptor?

答案:LipaseThe

rate-limting

enzyme

in

the

β-oxidation

of

fatty

acid

is

答案:carnitineacyltransferaseIWhichoneofthefollowingstatementsabouttheabsorptionoflipidsfromtheintestineiscorrect?

答案:Dietarytriacylglycerolispartiallyhydrolyzedandabsorbedasfreefattyacidsandmonoacylglycerol.Anewborninfanthadtroublebreathingatbirth.Theinfantwas3monthspremature.Thephysicianstreatedtheinfantwithasolution,whichwasdirectlyinjectedintothelungs.Withinseconds,theinfantrespondedwithmuchimprovedbreathing.Amajorcomponentofthissolutioniswhichoneofthefollowing?

答案:DipalmitoylphosphatidylcholineAllofthefollowingarederivedfromcholesterolexcept:

答案:SqualeneApatientpresentsinyourofficewithveryhighlevelsofserumcholesterol.Hestatesthathehastriedtofollowthedietandexerciseregimenyougavehimlastyear.YoudecidethatthispatientwouldbenefitfromadrugsuchasLipitor(atorvastatin).Thisclassofdrugsiseffectiveintreatinghypercholesterolemiabecauseithaswhateffect?

答案:Inhibits

the

enzymeβ-hydroxyl-β-methylglutaryl-CoA

reductaseThesubcellularsiteofthebreakdownoflongchainfattyacidstoacetyl-CoAvia-oxidationis:

答案:ThematrixofthemitochondriaTheclassofdrugscalledstatinshaveprovedveryeffectiveagainsthypercholesterolemia,amajorcauseofatherosclerosisandassociatedcardiovasculardisease.Thesedrugsreduceplasmacholesterollevelsby:

答案:Inhibitingtheconversionof3-hydroxy-3-methylglutaryl-CoAtomevalonateinthepathwayforcholesterolbiosynthesisRate-limiting

enzyme

in

the

synthesis

of

ketone

bodies

is

答案:HMG-CoAsynthaseUnderconditionofstarvation,themajorfuelforthebrainis

答案:ketonebodiesApatientpresentsinyourofficewithveryhighlevelsofserumcholesterol.Afteraseriesoftests,youconcludethatthepatienthashighcirculatinglevelsofLDLcholesterol,buthasnormallevelsoftheliverLDLreceptor.Onepossibleexplanationforthisobservationiswhichofthefollowing?

答案:ThepatienthasamutatedformofapoproteinB-100A7-year-oldgirlhas11-monthhistoryoffoul-smellingdiarrhea.Uponfurtherinquiry,thefrequencyseemstobe4-6stoolsperday.Shehasalsohadtroubleseeingatnightinthepast2weeks.HerWBCcountisnormal.Physicalexaminationisentirelynormal.Examinationofastoolsamplerevealsthatitisbulkyandgreasy.Analysisdoesnotrevealanypathogenicmicroorganismsorparasitesbutconfirmsthepresenceoffats.Furtherevaluationofthispatientwouldlikelyrevealwhichofthefollowingconditions?

答案:BiliaryinsufficiencyWhichoneofthefollowingstatementsconcerningchylomicronsisCORRECT?

答案:ChylomicronremnantsdifferfromchylomicronsinthattheyaresmallerandcontainalowerproportionoftriacylglycerolAftertheyareproducedfromacetyl-CoAintheliver,ketonebodiesaremainlyusedforwhichoneofthefollowingprocesses?

答案:GenerationofenergyinthetissuesTheactivatedcholinerequiredforthelecithinbiosynthesisis

答案:CDP-cholineThe

compound

which

can

not

be

oxidized

into

CO2

and

H2O

in

vivo

is

答案:cholesterolSynthesisoffattyacidsoccursinthecytoplasm,andiscatalyzedbyfattyacidsynthase.Inanimals,fattyacidsynthaseisahomodimer,witheachchainapproximately250,000Daltonsinsize.Thetwochainsarelinkedheadtotail.Allofthecomponentsoffattyacidsynthase,includingacylcarrierprotein(ACP)and

β-ketoacylACPsynthase,arecontainedwithinthetwochains.Reactionsoccurinthespacebetweenthetwochains,anarrangementthatkeepsthereactantsinoneplace.Thefirstroundofsynthesisproducesa4-carbonunit.Fromhere,twocarbonsareaddeduntilthefinalproduct,palmitateismade.Howmanyroundsdoesittaketomakepalmitate?

答案:7Youareexaminingapatientwhoexhibitsfastinghypoglycemiaandneedtodecidebetweenacarnitinedeficiencyandacarnitineacyltransferase2deficiencyasthepossiblecause.Youorderabloodtesttospecificallyexaminethelevelsofwhichoneofthefollowing?

答案:Acyl-carnitineWhichisthefollowingcantransferacetylgroupfrommitochondriatocytoplasm

答案:SuccinateA19-year-oldmancomplainsof“brownurine”andpaininthemusclesofhisarmsandlegsexperiencedwhileplayingtouchfootball.Hehashadseveralepisodesofmusclepainduringexercise,buthehadnotnoticeddarkeningofhisurineafterward.Thepainusuallyresolvedovernight.Physicalexaminationrevealsawell-fedmaleofnormalstature.Reflexesandrangeofmotioninallarmsandlegsarenormal,butthereissomeparaparesis(weakness),especiallyinhisrightleg.Amusclebiopsyistakenandsentforspecializedresting.Thepatientissenthomewitharecommendationtotakeadietarycarnitinesupplement.Whichofthefollowingisthemostlikelydiagnosis?

答案:CarnitinepalmitoyltransferasesIIdeficiencyIn

liver,

large

numbers

of

acetyl

CoA

derived

from

fat

mobilization

convert

mainly

into

答案:ketonebodies線粒體外NADH經(jīng)α-磷酸甘油穿梭作用，進(jìn)入線粒體內(nèi)實(shí)現(xiàn)氧化磷酸化，其p/o值為

答案:1.5線粒體中跨膜質(zhì)子濃度梯度建立后是

答案:線粒體內(nèi)膜外側(cè)的質(zhì)子濃度高于內(nèi)側(cè)的質(zhì)子濃度WhydoestheoxidationofNADHleadtoroughly3ATPs,whileFADH2oxidationproducesonlyabout2ATPs?

答案:Redox

potential

change

is

only

sufficient

for

production

of

2

ATPs.

AresearchwasstudyingoxidativephosphorylationinasuspentionofcarefullywashedandisolatedmitochondriaATP,ADP,inorganicphosphate,lactate,lactatedehydrogenase,andoxygenwereintroducedtothesuspension,andhewasabletodemonstrateATPproductionwithinthemitochondria.Theresearchwethenaddedoligomycintothemixture,whichstoppedoxygenuptake.Thisoccurredduetowhichofthefollowing?

答案:Inhibition

of

the

proton

translocating

ATPase關(guān)于生物氧化的描述哪一項(xiàng)是錯(cuò)誤的？

答案:CO2與反應(yīng)物中的C、H直接化合下列化合物中除()外都是呼吸鏈的組成成分。

答案:CoAWhichoffollowingsubunitismainlyresponsibletocatalyzethesynthesisofATPinATPsynthase?

答案:βWhat

is

the

consequence

of

thermalgenin

effect.

答案:ProducingmoreheatHowmanynetmoleculesofATParegeneratedintheconversionofglucosetopyruvate?

答案:2Aninfantwithanenlargedliverhasaglucose6-phosphatasedeficiency.Thisinfant

答案:cannotmaintainbloodglucoselevelseitherbyglycogenolysisorbygluconeogenesisWhichofthefollowingstatementsaboutglycolysisisTRUE?

答案:Glucokinasecatalyzestheconversionofglucosetoglucose6-phosphateintheliverInwhichcompartmentofthecelldoesglycolysisoccur?

答案:Solublecytoplasm(cytosol)Thedegradationofglycogennormallyproduces

答案:moreglucose1-phosphatethanglucoseThecompoundwhichcannotbeconvertedintoglucoseisinanimals.

答案:fattyacidTheprinciplfunctionoftheTCAcycleisto

答案:transferelectronsfromtheacetylportionofacetylCoAtoNAD+andFADWhichenzymeisthekeyenzymeinglycogenolysis(glycogendegradation)?

答案:PhosphorylaseTheuniquepathwayformatureredbloodcellstoobtainATPis

答案:glycolysisWhichcoenzymeinpyruvatedehydrogenasecomplexservesasthefinalhydrogensacceptor?

答案:NAD+Whichofthefollowingmetabolicpathwaytakeplaceinthemitochondira?

答案:thesynthesisofketonebodyMostofthereducingequivalentsutilizedforsynthesisoffattyacidscanbegeneratedfrom

答案:ThepentosephosphatepathwayAtwoyear-oldboywasbroughtintotheemerge