第1題Whichwavelength(nm)isusedinthecolorimetricassay?(

)A380B450C620D560第2題Theconcentrationofsulfuricacidusedtopreparetheanthronereagentis(

).A25%B98%C80%D50%第3題Thestandardcarbohydratesolutionusedinthisexperimentis().A1.0mg/mLglucosesolutionB0.1mg/mLglucosesolutionC0.1mg/mLsucrosesolutionD1.0mg/mLsucrosesolution第4題Thisexperimentisusedtodeterminethe()contentinplants.AtotalsolublecarbohydrateBsolublereducingcarbohydrateCtotalcarbohydrateDcellulose第5題Anthronecolorimetricassaycouldbeusedtodeterminewhichofthefollowingsubstances?(

)AmonosaccharideBstarchCfructoseDglycogen正確答案：ABCD第6題Beforeaddingtheanthronereagent,thetesttubeshouldbecooledinanicewaterbath.()第7題Differentcarbohydratesreactwithanthronereagents,exhibitingdifferentcolordarkness.()第8題Whenthecarbohydratesamplecontainsproteins,itcanbedirectlymeasuredwithoutremovingtheproteinsinadvance.()第9題Carbohydrateisdehydratedbytheconcentratedsulfuricacidtoproducefurfuralorhydroxymethylfurfural.Furfuralorhydroxymethylfurfuralcanreactwith____toproducesomeblue-greenfurfuralderivatives.正確答案：:Anthrone第10題Afteraddingtheanthronereagent,solventsneedtobeaccuratelyheatedinaboilingwaterbathfor____minutestocompletethereaction.正確答案：:10第1題TheroleofI2-KIsolutionis().AIndicatingwhethertheextractiscompletelyhydrolyzed.Thesolutionturnsblueifhydrolysisiscompleted.BIndicatingthattheextractcontainsamylopectin,anditturnsblueifstarchcontaining.CIndicatingwhethertheextractiscompletelyhydrolyzed.Thecompletedhydrolysissolutiondoesnotturnblue.DIndicatingwhetherthepHvalueisacidic.第2題Whichofthefollowingstatementsaboutthisexperimentarecorrect?()AReducingcarbohydrateisreductiveandcontainfreealdehydegroupsorketonegroups.BTotalcarbohydrateincludesreducingcarbohydrateandnon-reducingcarbohydrate.CWhendeterminingthetotalcarbohydrateinthisexperiment,itisnecessarytofirstlyhydrolyzethetotalcarbohydratetoreducingcarbohydrateunderacidicconditions.DItisnecessarytoconstructastandardcurveusingseveralconcentrationsofstarchsolution.正確答案：ABC第3題Whenextractingthetotalcarbohydrateofthesample,treatmentwithconcentratedHClisintendedtocompletelyhydrolyzethetotalcarbohydrateintomonosaccharides.NeutralizationtheHClwithNaOHbeforemeasurementisintendedtokeepthealkalineenvironmentof3,5-dinitrosalicylicacidreagentaswellastheprogressionofthereaction.()第4題AfteraddingDNSreagenttothesample,thetimeoftheboilingwaterbathdoesnotneedtobestrictlycontrolled.()第5題Theadditionofcrystallinephenoltothe3,5-dinitrosalicylicacidreagentisintendedtoenhancethecolor-reactionefficiencyofthereagent.()第6題Additionofsodiumsulfitetothe3,5-dinitrosalicylicacidreagentcouldeliminatetheinfluenceofdissolvedoxygeninthereagentandstabilizethereagent.()第7題____:Aseriesofcomplicatedreactionsbetweenreducingcarbohydrateandaminoacids/proteinswhenheated.Itwillproducebrownorblackmacromolecularsubstances,andintermediatemoleculeswithdifferentodors,includingreducingketones,aldehydesandcycliccompounds,providingattractiveflavorandcolorforfood.正確答案：:Maillardreaction第8題Inconstructingthestandardcurveofreducingcarbohydrate,DNSreagent____beaddedtotheblanktube(fillin"should"or"shouldnot")正確答案：:should第9題Whenmeasuringthecontentofreducingcarbohydrateby3,5-dinitrosalicylicacidmethod,thewavelengthis____nm.正確答案：:5407.Homework第1題Thestandardofconstantweightintheexperimentisthatthedifferencebetweenthetwoweightsdoesnotexceed()mg.A0.2B1C2D5第2題TheSoxhletextractionusedinthisexperimentisbasedon(

).Aweight-lossmethodBgravimetricanalysismethodCresiduemethodDimmersionmethod第3題Whichfollowingsubstancescannotbeusedaslipidextractionsolvents(

).AetherBpetroleumetherCethylacetateDwater第4題Whichofthefollowingsubstancesbelongtocrudefat?(

)AfreefattyacidBphospholipidCcelluloseDsterol正確答案：ABD第5題Inthisexperiment,thecrudelipidsareextractedwithpetroleumether.Ifthetemperatureisnotenoughhigh,analcohollampcanbeused.()第6題Afterextraction,thesmallflaskcontainingthecrudelipidssampleisdriedat103-105°Cfor30min.Becarefulnottooverheat.()第7題Onlywhentheheightoftheliquidlevelintheextractionchamberishigherthanofvaportube,thesolutionintheextractionchambercouldflowbacktothesmallflaskthroughthesiphonarm.()第8題Beforeextraction,thefilterpaperbagcontainingthesampleshouldbeplacedinthe____.正確答案：:Extractionchamber第9題Soxhletextractorisarefluxdevice,whichiscomposedofasmallflask,____andacondenser.正確答案：:Extractionchamber第10題Theheatinginstrumentusedfortheextractionofcrudelipidsis____.正確答案：:thermostatwaterbath7.Homework第1題TheAcidValueismeasuredbythemilligramsofpotassiumhydroxideneededtoneutralizethefattyacidsin100goflipids.()第2題WhenKOHisreplacedwithNaOHatthesameconcentrationasthetitrationalkaline,onlythemolecularweightofKOHneedstobereplacedwiththemolecularweightofNaOHincalculatingtheacidvalue.(

)第3題Dissolvelipidsinthealcohol/ethermixturewhichistitratedinadvance.How

willthesolventcolorchange?Whichoneisthecorrectexplanationofthecolorchange?(

).AThesolutionchangesfrompaleredtocolorless.Becausethefattyacidsinthelipidsmakethesolutionacidic.BThesolutionchangesfromcolorlesstopalered.Becausethefattyacidsinthelipidsmakethesolutionacidic.CThesolutionchangesfromcolorlesstopalered.Becausethefattyacidsinthelipidsreactwithalcohol-ether.DThesolutionchangesfrompaleredtocolorless.Becausethelipidsreactwithindicatorreagent.第4題Hydrolysisoflipidsreleasesfreefattyacids,whichwillbeoxidizedtoproducealdehydesorketonesintheair,creatingsome

bad

smell.Thisphenomenoniscalled

____oflipid.正確答案：:Rancidity第5題Thetitrationiscompletedasthesolutionturns(

).APalered,maintainingwithoutfadingBDarkred,maintainingwithoutfadingCPalered,maintainingfor1minutewithoutfadingDDarkred,maintainingfor1minutewithoutfading第6題Inordertodeductthebackground,thealcohol-ethermixtureis

usedtodissolvethelipids

needstobetitratedinadvance.(

)第7題Whichofthefollowingindicatorsareusedtomeasurethefreshnessoflipid?(

)AIodinevalueBAcidvalueCPeroxidevalueDMalonaldehydevalue正確答案：BCD第8題Which

of

thefollowingstatementaboutacidvalueiscorrect(

).AThelowertheacidvalue,thelessoffreefattyacidscontent,andthebetterofthelipidquality.BThelower

theacidvalue,themoreoffreefattyacidscontent,andthebetterofthelipidquality.CThelowertheacidvalue,thelessoffreefattyacidscontent,andthepoorerofthelipidquality.DThelowertheacidvalue,themoreoffreefattyacidscontent,andthepoorerofthelipidquality.第9題Acidvalueisoneofthestandardstomeasurethecontentof____infat.正確答案：:Freefattyacids7.Homework第1題What

isthegeneralproceduretodeterminetheN-terminalaminoacidofaproteinorpeptidebyDansylmethod(

).ADNSmodification→

Acidhydrolysis→

SeparationandidentificationbychromatographyBAcidhydrolysis→

DNSmodification→

SeparationandidentificationbychromatographyCAcidhydrolysis→

Separationbychromatography→

DNSmodificationandidentificationDDNSmodification→

Separationandidentificationbychromatography第2題Accordingtotheresultsofthisexperiment,DNS-Gly(A)andDNS-Leu(B)willmigrate

inthemobilephasesolutionI(benzene-glacialaceticacidsolution).Theonewiththehighestmigrationvelocityis____(fillin"A"or"B").正確答案：:B第3題Theretardationfactor

Rf

ofthesampleistheratioofthedistancefromtheloading

spottothechromatographyspot

____andthedistancefromtheloading

spottothesolventfront.正確答案：:center第4題Whenloading,thespotdiametershouldbecontrolledwithin2mmandthefilmisdriedwithhotwind.(

)第5題WhichofthefollowingaminoacidswillproducemorethanoneDNS-modifiedproducts?

()ALysBHisCTyrDLeu正確答案：ABC第6題We

can

observethechromatographicresultsunder____.Notethattheobservationtimeshouldnotbetoolonginordertoprotectyoureyes.正確答案：:UltravioletLamp第7題DNS-OHisaby-productofthis

reactionandcould

bedistinguishedfromDNS-aminoacidsby

itsbluefluorescence.(

)第8題Chromatographyisaseparationmethodbasedonthedistributioncoefficientdifferenceofcomponentsinthemixturebetweenthestationaryphaseandmobilephase.Thegreaterthedifferenceofdistributioncoefficientthebettertheseparationefficiency.第9題Inthisexperiment,whichof

thefollowingstatementsarecorrect().AAfterthepreparationofDNS-ClsolutionwithaminoacidsandpHadjustment,themixtureisincubatedtoreactin40°Cwaterbathfor2hoursindark.BTakeapieceofpolyamidefilmwithitsobversesideupward.Drawanintersectionlinewithapencilat1.0cmawayfromeachedge.Intersectionoftwolinesistheloadingspot.CAfterloading,curlthepolyamidefilmwithpolyamidesideoutward.Avoidcontactofbothsidesandthentiethefilmrollwithrubberbands.DNotethattheheightofthemobilephaseishigherthanthatofthespottingpoint.正確答案：AC第10題WhenpreparingDNS-aminoacid,whichoneofthepHrangesis

required?A5.5-7.5B6.0-9.0C7.5-9.5D9.0-10.5第11題DNS-aminoacidscanemit()fluorescenceunderultravioletlight.ALightblueBBlue-greenCYellow-greenDLightpink7.Homework第1題Whichofthe

followingstatementiswrong(

).AResinisinertinsolublepolymer.BThefunctionalgroupofthecationexchangeresinisacidic.CThefunctionalgroupoftheanionexchangeresinisalkaline.DThedissociableOH-ofthecationexchangeresincould

exchangewithcationsinthesolutionphase.第2題Bypretreatmentof

freshresin,theimpurities,suchasresidualsolvents,oligomersandafewheavymetalions(suchasFe3+,Cu2+),could

beremoved(

)第3題Pre-equilibrateisrequiredafterpacking.(

)第4題Besidesionexchangecolumnchromatography,otherchromatographytechniquesinclude(

).AHydrophobicchromatography:Substanceshavedifferentaffinitiestothehydrophobicgroupscoupledwiththeresin.BAffinitychromatography:Substancesbindtothespecificgroupsoftheresinwithdifferentaffinities.CGelfiltrationchromatography:Itisbasedonthemolecularweightdifferenceofseparatedcomponents.DIsoelectricFocusing:The

differenceinisoelectricpointamong

theseparatedsubstances.Itisbasedontheisoelectricpointdifferenceofseparatedcomponents.正確答案：ABCD第5題Which

of

thefollowingstatementis

correct?(

)AWhentheisoelectricpointpI<pH,theproteinispositivelychargedandcanbindwiththecationexchangeresin.BWhentheisoelectricpointpI<pH,theproteinisnegativelychargedandcannotbindwiththecationexchangeresin.CWhentheisoelectricpointpI>pH,theproteinispositivelychargedandcanbindwiththecationexchangeresin.DWhentheisoelectricpointpI>pH,theproteinisnegativelychargedandcannotcombinewiththecationexchangeresin.正確答案：BC第6題Whichofthefollowingmethodisbasedonthechargedifferencecarried

by

the

chargedmoleculestoseparatediversesubstances?(

)AHydrophobicchromatographyBAffinitychromatographyCIonexchangechromatographyDGelfiltrationchromatography第7題Theresinshouldbeaddedintothecolumn____(fillin“slowly”or“quickly”)toavoidproducingairbubbles.正確答案：:slowly第8題Accordingtothedifferentnumbers

ofaminoandcarboxylgroupscontainedinaminoacids,aminoacidsaredividedintothreecategories:acidicaminoacids,____aminoacidsandbasicaminoacids.正確答案：:neutral7.Homework第1題InordertoobtainanaccuratepH,itisbesttouseapH

meterformeasurement.(

)第2題Beforeprecipitating,bothmilkandacetate-sodiumacetatebuffershouldbepre-incubated

inawaterbathat____℃

forawhile.正確答案：:40第3題WhenthepHofthesolutionisequal

to

theisoelectricpointoftheprotein,thesolubilityoftheproteinisthe____(fillin"highest"or"lowest")正確答案：:lowest第4題Inthisexperiment,concentratedhydrochloricacidcould

beusedinsteadofglacialaceticacidtoadjustpH.(

)第5題Caseiniswhiteandodorless.Itisinsolubleinwater

andorganicsolventssuchasethanol,butsolubleinalkalinesolutions.(

)第6題Inthepresentexperiment,whatisthepossiblereasonthat

leads

to

thecontentofthecaseinhigherthanthetheoreticaloractualvalue?()AThe

pHadjustedbyglacialaceticacidreachesto3.BSomewheyproteinswillprecipitateduringtheheating

process.CThemilkgoesbad.DRinsingisincompleteandcausesotherimpuritiesinproteinsample.正確答案：BD第7題Regardingthepreparationofcaseininmilk,which

of

thefollowingstatementis

correct().ACaseinisthemostabundantproteininmilkBGlacialaceticacidisusedtoadjustthepHofmilk.ProteinwillprecipitateifthepHofthesolventisnearitsisoelectricpoint.CSomewheyproteinswillalsoprecipitateoutwhileheated.DInthepurificationofcasein,differentrinsingsolventsisusedinsequence.正確答案：BCD第8題Theisoelectricpointofcaseinis(

).A3.0B4.7C7.0D7.6第9題Themost

abundantproteininmilkis(

).AWheyproteiBAlbuminCCaseinDGlobulin7.Homework第1題Whichofthefollowingmethoddoesnotconsumeproteinsamples,andtheproteincanstillberecycled

aftermeasurement(

).ABiuretmethodBUltravioletabsorptionmethodCFolin-phenolreagentmethod(Lowrymethod)DKjeldahlmethodECoomassieBrilliantBluemethod第2題Thedetectionwavelengthis

at

____nminCoomassieBrilliantBluemethodfordeterminationofproteinconcentration.正確答案：:595第3題Ultravioletabsorptionmethod

canbeusedtoidentifythepurityofprotein.Whenthecontent

of

nucleicacidinthesampleincreases,thevalueofA280nm/A260nmwill____(fillin"increase"or"decrease")正確答案：:decrease第4題WhenusingCoomassieBrilliantBluemethodtomeasureproteins,whichofthefollowingfactorswillinterferewiththeresults?(

)APotassiumionsBMagnesiumionsCEthanolDTritonX-100第5題WhenusingtheCoomassiebrilliantbluemethodtodetermineprotein,theproteincontentofthesampleshouldbe10-100μg.(

)第6題Whenusingultravioletabsorptionmethodtodetermineproteinsamples,quartzcuvetteshouldbeusedinsteadofglasscuvette.(

)第7題Whatfactorsshouldbeconsideredinthemethodsselectionofproteinconcentrationdetermination?(

)AThepropertiesoftheanalyzedproteinBThesensitivityandaccuracyrequiredintheexperimentCInterferingsubstancespresentinthesolutionDThetimeittakestodeterminetheproteinconcentration正確答案：ABCD第8題Which

istheinternationalstandardmethodfordeterminationofproteincontent?(

)ABiuretmethodBUltravioletabsorptionmethodCCoomassieBrilliantBluemethodDKjeldahlmethod第9題Whichoffollowingaminoacidshaveconjugateddoublebonds?(

)ATyrosineBTryptophanCAlanineDPhenylalanine正確答案：ABD第10題Besides

CoomassieBrilliantBluemethod,()methodscan

alsobe

used

to

determineproteinsconcentration.AKjeldahlmethodBBiuretmethodCFolin-phenolreagentmethod(Lowrymethod)DUltravioletabsorptionmethod正確答案：ABCD7.Homework第1題Aftertheproteinbandisleachedbytheleachingsolution,itisquantifiedbycolorimetricmethod

at____nm.正確答案：:590第2題Thesample

shouldbeloaded

onthecelluloseacetatemembrane____theshinyside(filledwith"with"or"without").正確答案：:without第3題Thestainingreagentusedinthisexperimentis(

).ACoomassieBrilliantBlueG250solutionBCoomassieBrilliantBlueR250solutionCAminoBlack10BsolutionDPonceauSsolution第4題Whichofthefollowingoperations

are

correctinserumproteinsseparationby

celluloseacetatemembraneelectrophoresis?

(

)ABeforeloading,spongeuptheexcesselectrophoresisbufferonthesurfaceofthefilmwithfilterpaper.BSomeserumsampleisdippedwiththecross-sectionofaspottingslideandgenerallykeeptheslide-filmcontactingfor2to3secondsduringloading,untiltheserumpenetratesthemembrane.CThewidthoftheloading

isshorter

thanthatofthemembrane,avoidloading

repeatedly.DToomuchloading

willresultinunclearbandboundaries.正確答案：ABCD第5題Inthisexperiment,theproteins

innormalhumanserumareseparatedandmigratedinto5bands.Thesequencefromanodetocathodeis:____,α1-globulin,α2-globulin,β-globulinandγ-globulin.正確答案：:Albumin第6題Theresultofnormalhumanserumbycelluloseacetatemembraneelectrophoresisisshownasfollows.Thepossiblereasonoftheunsatisfactoryseparationis(

)Atheloading

volumeistoolargeBloading

repeatedlyCtheloading

widthistoolargeDtheelectrophoresistimeistooshort第7題TheisoelectricpointofimmunoglobulininserumismostlyaroundpH7.Forexample,pIofIgMis7.0andpIofIgAis7.4.AftercelluloseacetatemembraneelectrophoresisusingpH8.6barbituratesodiumelectrodebuffer,whichregionwillthesetwoproteinslocateat?(

)AnearAlbuminBnearα1-globulinCnearα2-globulinDnearβ-globulinEnearγ-globulin正確答案：E第8題ThepHoftheelectrodebuffercommonlyusedtoseparateserumproteinsbycelluloseacetatemembraneelectrophoresisis(

).A4.8B5.8C6.8D8.6第9題Proteinsseparatedbycelluloseacetatemembraneelectrophoresisarequantifiedaccordingtothewidthofeachbandafterelectrophoresis.(

)第10題Theproteinsampleseparatedbycelluloseacetatemembraneelectrophoresiscanberecycledandreused.(

)第11題Celluloseacetatemembraneelectrophoresishaslowerresolutionthanpolyacrylamidegelelectrophoresis(PAGE)in

proteinsseparation.(

)7.Homework第1題InSDS,thegreatertherelativemolecularmassoftheprotein,the____therelativemigrationratewillbe.

(Fillin"faster"or"slower").正確答案：:slower第2題SDSgelisdividedintoupperandlowerparts,thelowerpartiscalled____.正確答案：:separatinggel第3題In

SDS,reducingsubstancesareusedtobreakdisulfidebonds.Therefore,themolecularweightsofthesubunitsorsinglechainswill

be

actuallymeasured.(

)第4題InSDS,proteinsmovefromanodetocathode.(

)第5題InSDS,themigrationrateofproteinsonlydependsonthemoleculesizeandhasnothingtodowiththechargeandmoleculeshape.(

)第6題Thesampleshouldbeboiledfor10minutesbeforeloading.(

)第7題TheroleofSDSinthisexperimentis(

).APrecipitateproteinBBindwithproteinmoleculesinacertainproportionCLettheproteinscarrylargeamountofnegativechargestoeliminatetheoriginalchargedifferenceDFullydepolymerizeproteinsintomonomers正確答案：BC第8題Afteraddingtheseparatinggelsolutionintothegapbetweentwoglassplates,itisnecessarytocovertheseparatinggel

withalayerofwaterimmediately.Thepurposeofthisoperationis(

).Aeliminating

bubblesBpreventing

oxygenfromdiffusingintothegelandinterferingwithpolymerizationCdiluting

thegelDspeeding

upthegelpolymerization正確答案：AB第9題Ingeneral,theconcentrationofstackinggelindiscontinuousSDS

is(

).A5%B8%C12%D10%第10題ThepHofSDSelectrophoresisbufferis(

).A8.3B8.8C6.8D7.07.Homework第1題DNA-binding

proteins

(DNP)existsinthenucleusandisslightlysolubleinhighsaltsolution(1mol/L)andsolubleinlowsaltsolution(0.14mol/L).()第2題Incells,DNAorRNAareusuallyprotein-binding.(

)第3題SDScan

removethe____boundwith

DNAduringtheDNAextractionprocedure.正確答案：:proteins第4題DuringDNAextraction,chloroform-isoamylalcoholandSDSareadded.Aftercentrifugation,thelayers

areshows

inthe

figure.Which

of

thefollowingstatementsarecorrect?(

)ATheupperlayerisanaqueousphasecontainingDNA,themiddlelayerisdenaturedproteins,andthelowerlayerischloroform.BTheupperlayerischloroform,themiddlelayerisdenaturedprotein,andthelowerlayerisanaqueousphasecontainingDNACSDScandestroytheadvancestructureofproteinsandcausetheproteinstodissociatefromDNA.DChloroformisaproteinsdenaturant,whichcanprecipitateproteinandacceleratetheseparationoforganicphaseandaqueousphase.正確答案：ACD第5題RegardingtheextractionstepsofanimalliverDNA,which

of

thefollowingstatementsarecorrect?(

)ALargepiecesoflivertissuecould

bedirectlyhomogenized.BWhentheglassrodiswrappedaroundwithDNA,itshouldbestirredquicklyinthesamedirection.CDNAextractionprocessshouldavoidexcessiveacid,alkali,hightemperatureanddamageby

mechanicaltension.DNaClpowdershouldbeaddedinbatchesandshakenasitisaddedtoavoidhighlocalsaltconcentration.正確答案：CD第6題ToquantifyDNAwiththediphenylaminecolorimetricmethod,theabsorbance

value

shouldbemeasuredat____nm.正確答案：:595第7題WhenextractingliverDNA,whichofthefollowingconcentrationofsaltsolutioncoulddissolveDNAthebest?(

)A0.05mol/LB0.5mol/LC1mol/LD10mol/L第8題DNAreacts

withdiphenylaminereagentinboilingwaterbathandtheproductturns(

).ApurpleBgreenC

blueDyellow第9題Diphenylaminecolorimetricmethodcould

beusedtoidentify(

).ADNABRNACallnucleicacidsDbases7.Homework第1題Orcinolmethod

forRNAquantificationisbasedontheconversionof____intheRNAmoleculetoα-furanformaldehydeunderstrongacidconditions.α-furanformaldehydecanspecificallyreactwithorcinol,showinggreencolor.正確答案：:ribose第2題WhichofthefollowingoperationofyeastRNAextractionisincorrect?(

)AExtractionwithNaOHsolutionmustbeperformedat4°CtoensurethebiologicalactivityofRNA.BAftercentrifugation,carefullyaspiratethesupernatantwithadropper,anddonotsuckthelowercelldebris.Ifthesupernatantisstillturbid,centrifugeagain.CWhenwashingcrudeRNA,becarefulnottosplashwater.Otherwise,theproductwillbeverystickyanddifficulttobecollected.DOrcinolsolutionispreparedwithconcentratedhydrochloricacid.Therelatedoperationsmustbeperformedinafumehood.第3題RNAmoleculeiscomposedofphosphoricacid,deoxyriboseandbase.(

)第4題Yeast(Saccharomyce),oneoftheprokaryoticmodels,iscommonlyappliedingenecloningexperiment.(

)第5題Which

of

thefollowingstatementiswrong?

(

)ATheRNAextractedbythedilutealkalimethodisdenatured,whichcanbeusedforRNAcomponentidentificationandsinglenucleotidepreparation.However,itcannotbeusedtomeasurethebiologicalactivityofRNA.BAllpentosescould

reactwithorcinol,soorcinoltestcannotbeusedasthebasisforRNAandDNAidentification.CInadditiontodirectlyprecipitatingRNAwithethanol,RNAcanalsobeprecipitatedbyadjustingthepHofthesolutionto4-4.5,

theisoelectricpointofRNA.DTheboilingwaterbathunderdilutealkaline

istolyse

theyeastcellsandreleaseRNA.正確答案：BC第6題InextractingyeastRNAextractionandorcinolquantification,which

of

thefollowingoperationsare

correct?

(

)AThe

extracting

shouldbeconducted

at4℃.BAfterextractionofRNA,adjusttheextractionsolutiontopH5-6withaceticacid.CRNAsuspensionissuctionfiltered.

Thefilterresidueiswashedtwicewith95%ethanolandtwicewithanhydrousetherinsequence.DBecausehydrochloricacidisvolatile,orcinolreagentshouldbeadded

inafumehood.正確答案：BCD第7題Whichofthefollowingmethodscan

be

used

toquantifyRNA?(

)APhosphorusdeterminationmethodBCarbohydratedeterminationmethodCDiphenylaminemethodDSDSelectrophoresismethod正確答案：AB第8題ToquantifyRNAbyorcinolcolorimetricmethod,theabsorbanceshouldbemeasuredat(

).A280nmB620nmC595nmD670nm7.Homework第1題SDSisananionicsurfactant,whichhelpsbacterialyseandkeeptheproteinmaintaininganaturalactivity.(

)第2題____istheindependentgeneticfactoroutofchromosomeinbacterial.

Itcouldself-replicateautonomouslyandstablyinheritcertaintraitsofbacteria.正確答案：:Plasmid第3題Naturalplasmidsarecircularsingle-strandedDNA.(

)第4題Inthefinalstepofplasmidextraction,addthe

eluenttothecenteroftheadsorptioncolumn,andleaveitatroomtemperaturefor2minutestofullydissolvetheplasmidDNAwhich

has

been

adsorbedby

thecolumn.(

)第5題Inthe

presentexperiment,the

forefrontbandat

about100bpobserved

underultravioletlightis____.正確答案：:ResidualRNA第6題TheroleofDuReddyeinagarosegelelectrophoresisis(

).AParticipateintheformationofporestructureBPre-stainthe

gel.Therefore,theplasmidDNAcould

emit

fluorescenceat

300nm,whichiseasily

observedCDenatureplasmidDNADIndicatethe

positionofforefrontbandin

electrophoresis第7題Accordingtothehydrolyticcharacteristics,

catalyticconditionsandmodificationcapacity,restrictionenzymescould

bedividedinto(

).ATypeIBTypeIICTypeIIIDTypeIV正確答案：ABC第8題Inthisexperiment,iftheunexpectedresultsare

shown

afteragarosegelelectrophoresis,thepossiblereasons

are

().AThepurityoftheplasmidDNAislowandtheimpurityproteinsarenotremovedcompletelyBImproperselectionofreactionbuffersystemCTheamountofenzymeanddigestiontimeareinappropriateDAlltheaboveanswersarecorrect正確答案：ABCD第9題Thereagent

of

thefirststepinthealkalinelysismethodoftencontainsEDTA.Itsfunctionisto(

).AhelatingmagnesiumandcalciumionstoinhibitDNaseactivityBpromotingRNAhydrolysisClysingbacteriaDadjustingpH7.Homework第1題Whataretherolesof25%sulfuricacidintheexperiment?(

)ADenature

enzymetostoptheenzymaticreaction.BProvidetheacidicenvironmentrequiredforKMnO?titr