Experiments in Biochemistry（生物化學(xué)實(shí)驗(yàn)）-南京大學(xué)中國大學(xué)mooc課后章節(jié)答案期末考試題庫2023年

ExperimentsinBiochemistry（生物化學(xué)實(shí)驗(yàn)）_南京大學(xué)中國大學(xué)mooc課后章節(jié)答案期末考試題庫2023年DNS-OHisaby-productofthisreactionandcouldbedistinguishedfromDNS-aminoacidsbyitsbluefluorescence.()

參考答案:

正確

InSDS,proteinsmovefromanodetocathode.()

參考答案:

錯(cuò)誤

InSDS,themigrationrateofproteinsonlydependsonthemoleculesizeandhasnothingtodowiththechargeandmoleculeshape.()

參考答案:

正確

Inthefinalstepofplasmidextraction,addtheeluenttothecenteroftheadsorptioncolumn,andleaveitatroomtemperaturefor2minutestofullydissolvetheplasmidDNAwhichhasbeenadsorbedbythecolumn.()

參考答案:

正確

Makesuretheaccuracyofthetemperatureandreactiontimeoftheenzymaticreactiontoensuretheidenticalconditionsofeachreactionsystem.()

參考答案:

正確

Inthepresentexperiment,whatisthepossiblereasonthatleadstothecontentofthecaseinhigherthanthetheoreticaloractualvalue?()

參考答案:

Rinsingisincompleteandcausesotherimpuritiesinproteinsample._Somewheyproteinswillprecipitateduringtheheatingprocess.

InextractingyeastRNAextractionandorcinolquantification,whichofthefollowingoperationsarecorrect?()

參考答案:

RNAsuspensionissuctionfiltered.Thefilterresidueiswashedtwicewith95%ethanolandtwicewithanhydrousetherinsequence._Becausehydrochloricacidisvolatile,orcinolreagentshouldbeaddedinafumehood._AfterextractionofRNA,adjusttheextractionsolutiontopH5-6withaceticacid.

Ifthereactionspeedineachconicalflaskisverysmall,howtosolvethisproblem?()

參考答案:

Increasetheextractionquantityandconcentrationoftheenzyme_Chooseappropriateextractionconditionstoavoiddenaturationordeactivationoftheenzyme_Chooseotherbiomaterialswithhighcatalaseactivity

WhichofthefollowingfactorsarerelatedtoKm?()

參考答案:

Substratespecies_Enzymespecies

Thestandardofconstantweightintheexperimentisthatthedifferencebetweenthetwoweightsdoesnotexceed()mg.

參考答案:

0.2

Ingeneral,theconcentrationofstackinggelindiscontinuousSDSis().

參考答案:

5%

WhichofthefollowingmethodscanbeusedtoquantifyRNA?()

參考答案:

Phosphorusdeterminationmethod_Carbohydratedeterminationmethod

Afteraddingtheseparatinggelsolutionintothegapbetweentwoglassplates,itisnecessarytocovertheseparatinggelwithalayerofwaterimmediately.Thepurposeofthisoperationis().

參考答案:

preventingoxygenfromdiffusingintothegelandinterferingwithpolymerization_eliminatingbubbles

WhatisthegeneralproceduretodeterminetheN-terminalaminoacidofaproteinorpeptidebyDansylmethod().

參考答案:

DNSmodification→Acidhydrolysis→Separationandidentificationbychromatography

Theproteinsampleseparatedbycelluloseacetatemembraneelectrophoresiscanberecycledandreused.()

參考答案:

錯(cuò)誤

Whatfactorsshouldbeconsideredinthemethodsselectionofproteinconcentrationdetermination?()

參考答案:

Thepropertiesoftheanalyzedprotein_Thesensitivityandaccuracyrequiredintheexperiment_Interferingsubstancespresentinthesolution_Thetimeittakestodeterminetheproteinconcentration

Whenloading,thespotdiametershouldbecontrolledwithin2mmandthefilmisdriedwithhotwind.()

參考答案:

錯(cuò)誤

Onlywhentheheightoftheliquidlevelintheextractionchamberishigherthanofvaportube,thesolutionintheextractionchambercouldflowbacktothesmallflaskthroughthesiphonarm.()

參考答案:

錯(cuò)誤

Whichwavelength(nm)isusedinthecolorimetricassay?()

參考答案:

620

Whenextractingthetotalcarbohydrateofthesample,treatmentwithconcentratedHClisintendedtocompletelyhydrolyzethetotalcarbohydrateintomonosaccharides.NeutralizationtheHClwithNaOHbeforemeasurementisintendedtokeepthealkalineenvironmentof3,5-dinitrosalicylicacidreagentaswellastheprogressionofthereaction.()

參考答案:

正確

Inthepresentexperiment,aftercalculatingthesubstrateconcentration([S])andthereactionrate(v),howtousethedoublereciprocaltoplot?()

參考答案:

1/vontheordinate,1/[S]ontheabscissa

ToquantifyRNAbyorcinolcolorimetricmethod,theabsorbanceshouldbemeasuredat().

參考答案:

670nm

Theisoelectricpointofcaseinis().

參考答案:

4.7

Regardingthepreparationofcaseininmilk,whichofthefollowingstatementiscorrect().

參考答案:

Inthepurificationofcasein,differentrinsingsolventsisusedinsequence._Somewheyproteinswillalsoprecipitateoutwhileheated._GlacialaceticacidisusedtoadjustthepHofmilk.ProteinwillprecipitateifthepHofthesolventisnearitsisoelectricpoint.

Trichloroaceticacidisastrongacidwhichcanacceleratetheenzymereactionbydenaturingenzymeprotein.()

參考答案:

錯(cuò)誤

Theproteinsampleseparatedbycelluloseacetatemembraneelectrophoresiscanberecycledandreused.()

參考答案:

錯(cuò)誤

Hydrolysisoflipidsreleasesfreefattyacids,whichwillbeoxidizedtoproducealdehydesorketonesintheair,creatingsomebadsmell.Thisphenomenoniscalled______oflipid.

參考答案:

rancidity

InordertoobtainanaccuratepH,itisbesttouseapHmeterformeasurement.()

參考答案:

正確

Celluloseacetatemembraneelectrophoresishaslowerresolutionthanpolyacrylamidegelelectrophoresis(PAGE)inproteinsseparation.()

參考答案:

正確

InSDS,proteinsmovefromanodetocathode.()

參考答案:

錯(cuò)誤

DNAreactswithdiphenylaminereagentinboilingwaterbathandtheproductturns().

參考答案:

blue

Incells,DNAorRNAareusuallyprotein-binding.()

參考答案:

正確

Theverticalaxisistheenzymereactionrateandthehorizontalaxisisthesubstrateconcentration.Whentheamountofenzymeisdoubled,whichfigurerepresenttherelationshipbetweensubstrateconcentrationandreactionrate()

參考答案:

B

WhatisthegeneralproceduretodeterminetheN-terminalaminoacidofaproteinorpeptidebyDansylmethod().

參考答案:

DNSmodification→Acidhydrolysis→Separationandidentificationbychromatography

Whichofthefollowingstatementaboutacidvalueiscorrect().

參考答案:

Thelowertheacidvalue,thelessoffreefattyacidscontent,andthebetterofthelipidquality.

TheSoxhletextractionusedinthisexperimentisbasedon().

參考答案:

gravimetricanalysismethod

Whatfactorswillaffectthereactionrateoftheenzyme?()

參考答案:

Enzymeconcentration_Temperature_Substrateconcentration_pH

Whichofthefollowingstatementiswrong?()

參考答案:

InadditiontodirectlyprecipitatingRNAwithethanol,RNAcanalsobeprecipitatedbyadjustingthepHofthesolutionto4-4.5,theisoelectricpointofRNA._Allpentosescouldreactwithorcinol,soorcinoltestcannotbeusedasthebasisforRNAandDNAidentification.

Whichofthefollowingoperationsarecorrectinserumproteinsseparationbycelluloseacetatemembraneelectrophoresis?()

參考答案:

Toomuchloadingwillresultinunclearbandboundaries._Someserumsampleisdippedwiththecross-sectionofaspottingslideandgenerallykeeptheslide-filmcontactingfor2to3secondsduringloading,untiltheserumpenetratesthemembrane._Thewidthoftheloadingisshorterthanthatofthemembrane,avoidloadingrepeatedly._Beforeloading,spongeuptheexcesselectrophoresisbufferonthesurfaceofthefilmwithfilterpaper.

Inthisexperiment,whichofthefollowingstatementsarecorrect().

參考答案:

AfterthepreparationofDNS-ClsolutionwithaminoacidsandpHadjustment,themixtureisincubatedtoreactin40°Cwaterbathfor2hoursindark._Afterloading,curlthepolyamidefilmwithpolyamidesideoutward.Avoidcontactofbothsidesandthentiethefilmrollwithrubberbands.

No.0conicalflaskissettoremovetheotherbackgroundsubstanceswhichcouldbereducedbyKMnO?.()

參考答案:

正確

Incells,DNAorRNAareusuallyprotein-binding.()

參考答案:

正確

Theadditionofcrystallinephenoltothe3,5-dinitrosalicylicacidreagentisintendedtoenhancethecolor-reactionefficiencyofthereagent.()

參考答案:

正確

Differentcarbohydratesreactwithanthronereagents,exhibitingdifferentcolordarkness.()

參考答案:

正確

Beforeaddingtheanthronereagent,thetesttubeshouldbecooledinanicewaterbath.()

參考答案:

正確

AfteraddingDNSreagenttothesample,thetimeoftheboilingwaterbathdoesnotneedtobestrictlycontrolled.()

參考答案:

錯(cuò)誤

Fromthe______,itcoulddeducethatwhichfactorhasthegreatestorleastinfluenceonenzymeactivity.

參考答案:

maximumdifference

Ultravioletabsorptionmethodcanbeusedtoidentifythepurityofprotein.Whenthecontentofnucleicacidinthesampleincreases,thevalueofA280nm/A260nmwill______(fillin"increase"or"decrease")

參考答案:

decrease

TheAcidValueismeasuredbythemilligramsofpotassiumhydroxideneededtoneutralizethefattyacidsin100goflipids.()

參考答案:

錯(cuò)誤

No.0conicalflaskissettoremovetheotherbackgroundsubstanceswhichcouldbereducedbyKMnO?.()

參考答案:

正確

Whichofthefollowingstatementsaboutthisexperimentarecorrect?()

參考答案:

Totalcarbohydrateincludesreducingcarbohydrateandnon-reducingcarbohydrate._Whendeterminingthetotalcarbohydrateinthisexperiment,itisnecessarytofirstlyhydrolyzethetotalcarbohydratetoreducingcarbohydrateunderacidicconditions._Reducingcarbohydrateisreductiveandcontainfreealdehydegroupsorketonegroups.

Beforeextraction,thefilterpaperbagcontainingthesampleshouldbeplacedinthe______.

參考答案:

Extractionchamber

Whenextractingthetotalcarbohydrateofthesample,treatmentwithconcentratedHClisintendedtocompletelyhydrolyzethetotalcarbohydrateintomonosaccharides.NeutralizationtheHClwithNaOHbeforemeasurementisintendedtokeepthealkalineenvironmentof3,5-dinitrosalicylicacidreagentaswellastheprogressionofthereaction.()

參考答案:

正確

InordertoobtainanaccuratepH,itisbesttouseapHmeterformeasurement.()

參考答案:

正確

TheretardationfactorRfofthesampleistheratioofthedistancefromtheloadingspottothechromatographyspot______andthedistancefromtheloadingspottothesolventfront.

參考答案:

center

Beforeextraction,thefilterpaperbagcontainingthesampleshouldbeplacedinthe______.

參考答案:

Extractionchamber

Additionofsodiumsulfitetothe3,5-dinitrosalicylicacidreagentcouldeliminatetheinfluenceofdissolvedoxygeninthereagentandstabilizethereagent.()

參考答案:

正確

Whenloading,thespotdiametershouldbecontrolledwithin2mmandthefilmisdriedwithhotwind.()

參考答案:

錯(cuò)誤

Proteinsseparatedbycelluloseacetatemembraneelectrophoresisarequantifiedaccordingtothewidthofeachbandafterelectrophoresis.()

參考答案:

錯(cuò)誤

Besidesionexchangecolumnchromatography,otherchromatographytechniquesinclude().

參考答案:

IsoelectricFocusing:Thedifferenceinisoelectricpointamongtheseparatedsubstances.Itisbasedontheisoelectricpointdifferenceofseparatedcomponents._Hydrophobicchromatography:Substanceshavedifferentaffinitiestothehydrophobicgroupscoupledwiththeresin._Gelfiltrationchromatography:Itisbasedonthemolecularweightdifferenceofseparatedcomponents._Affinitychromatography:Substancesbindtothespecificgroupsoftheresinwithdifferentaffinities.

Differentcarbohydratesreactwithanthronereagents,exhibitingdifferentcolordarkness.()

參考答案:

正確

ThereagentofthefirststepinthealkalinelysismethodoftencontainsEDTA.Itsfunctionisto().

參考答案:

helatingmagnesiumandcalciumionstoinhibitDNaseactivity

Vaccineincidentshaveattractedmuchattentionrecently.Similartovaccines,enzymeshouldbestoredatlowtemperaturebecause()

參考答案:

Hightemperaturedeprivesenzymeactivity

Ifthereactionspeedineachconicalflaskisverysmall,howtosolvethisproblem?()

參考答案:

Chooseotherbiomaterialswithhighcatalaseactivity_Chooseappropriateextractionconditionstoavoiddenaturationordeactivationoftheenzyme_Increasetheextractionquantityandconcentrationoftheenzyme

AfteraddingDNSreagenttothesample,thetimeoftheboilingwaterbathdoesnotneedtobestrictlycontrolled.()

參考答案:

錯(cuò)誤

Inthisexperiment,thecrudelipidsareextractedwithpetroleumether.Ifthetemperatureisnotenoughhigh,analcohollampcanbeused.()

參考答案:

錯(cuò)誤

Onlywhentheheightoftheliquidlevelintheextractionchamberishigherthanofvaportube,thesolutionintheextractionchambercouldflowbacktothesmallflaskthroughthesiphonarm.()

參考答案:

錯(cuò)誤

Theresultofnormalhumanserumbycelluloseacetatemembraneelectrophoresisisshownasfollows.Thepossiblereasonoftheunsatisfactoryseparationis()

參考答案:

theloadingwidthistoolarge

Thestainingreagentusedinthisexperimentis().

參考答案:

AminoBlack10Bsolution

Thetitrationiscompletedasthesolutionturns().

參考答案:

Palered,maintainingfor1minutewithoutfading

Dissolvelipidsinthealcohol/ethermixturewhichistitratedinadvance.Howwillthesolventcolorchange?Whichoneisthecorrectexplanationofthecolorchange?().

參考答案:

Thesolutionchangesfrompaleredtocolorless.Becausethefattyacidsinthelipidsmakethesolutionacidic.

TheroleofI2-KIsolutionis().

參考答案:

Indicatingwhethertheextractiscompletelyhydrolyzed.Thecompletedhydrolysissolutiondoesnotturnblue.

Thisexperimentisusedtodeterminethe()contentinplants.

參考答案:

totalsolublecarbohydrate

Thestandardcarbohydratesolutionusedinthisexperimentis().

參考答案:

0.1mg/mLglucosesolution

Theconcentrationofsulfuricacidusedtopreparetheanthronereagentis().

參考答案:

80%

TheAcidValueismeasuredbythemilligramsofpotassiumhydroxideneededtoneutralizethefattyacidsin100goflipids.()

參考答案:

錯(cuò)誤

WhenKOHisreplacedwithNaOHatthesameconcentrationasthetitrationalkaline,onlythemolecularweightofKOHneedstobereplacedwiththemolecularweightofNaOHincalculatingtheacidvalue.()

參考答案:

錯(cuò)誤

Inordertodeductthebackground,thealcohol-ethermixtureisusedtodissolvethelipidsneedstobetitratedinadvance.()

參考答案:

正確

WhenusingtheCoomassiebrilliantbluemethodtodetermineprotein,theproteincontentofthesampleshouldbe10-100μg.()

參考答案:

正確

Whenusingultravioletabsorptionmethodtodetermineproteinsamples,quartzcuvetteshouldbeusedinsteadofglasscuvette.()

參考答案:

正確

Pre-equilibrateisrequiredafterpacking.()

參考答案:

正確

Inthisexperiment,iftheunexpectedresultsareshownafteragarosegelelectrophoresis,thepossiblereasonsare().

參考答案:

Improperselectionofreactionbuffersystem_Theamountofenzymeanddigestiontimeareinappropriate_ThepurityoftheplasmidDNAislowandtheimpurityproteinsarenotremovedcompletely_Alltheaboveanswersarecorrect

Accordingtothehydrolyticcharacteristics,catalyticconditionsandmodificationcapacity,restrictionenzymescouldbedividedinto().

參考答案:

TypeII_TypeI_TypeIII

WhichofthefollowingmethodscanbeusedtoquantifyRNA?()

參考答案:

Phosphorusdeterminationmethod_Carbohydratedeterminationmethod

TheroleofSDSinthisexperimentis().

參考答案:

Bindwithproteinmoleculesinacertainproportion_Lettheproteinscarrylargeamountofnegativechargestoeliminatetheoriginalchargedifference

RNAmoleculeiscomposedofphosphoricacid,deoxyriboseandbase.()

參考答案:

錯(cuò)誤

Yeast(Saccharomyce),oneoftheprokaryoticmodels,iscommonlyappliedingenecloningexperiment.()

參考答案:

錯(cuò)誤

SDSisananionicsurfactant,whichhelpsbacterialyseandkeeptheproteinmaintaininganaturalactivity.()

參考答案:

錯(cuò)誤

Whenthecarbohydratesamplecontainsproteins,itcanbedirectlymeasuredwithoutremovingtheproteinsinadvance.()

參考答案:

錯(cuò)誤

Theadditionofcrystallinephenoltothe3,5-dinitrosalicylicacidreagentisintendedtoenhancethecolor-reactionefficiencyofthereagent.()

參考答案:

正確

______:Aseriesofcomplicatedreactionsbetweenreducingcarbohydrateandaminoacids/proteinswhenheated.Itwillproducebrownorblackmacromolecularsubstances,andintermediatemoleculeswithdifferentodors,includingreducingketones,aldehydesandcycliccompounds,providingattractiveflavorandcolorforfood.

參考答案:

Maillardreaction

Thestandardofconstantweightintheexperimentisthatthedifferencebetweenthetwoweightsdoesnotexceed()mg.

參考答案:

0.2

Inthisexperiment,thecrudelipidsareextractedwithpetroleumether.Ifthetemperatureisnotenoughhigh,analcohollampcanbeused.()

參考答案:

錯(cuò)誤

Theheatinginstrumentusedfortheextractionofcrudelipidsis______.

參考答案:

thermostatwaterbath

Whichofthefollowingstatementaboutacidvalueiscorrect?()

參考答案:

Thelowertheacidvalue,thelessoffreefattyacidscontent,andthebetterofthelipidquality.

Inordertodeductthebackground,thealcohol-ethermixtureisusedtodissolvethelipidsneedstobetitratedinadvance.()

參考答案:

正確

Inthisexperiment,whichofthefollowingstatementsarecorrect().

參考答案:

Afterloading,curlthepolyamidefilmwithpolyamidesideoutward.Avoidcontactofbothsidesandthentiethefilmrollwithrubberbands._AfterthepreparationofDNS-ClsolutionwithaminoacidsandpHadjustment,themixtureisincubatedtoreactin40°Cwaterbathfor2hoursindark.

DNS-OHisaby-productofthisreactionandcouldbedistinguishedfromDNS-aminoacidsbyitsbluefluorescence.()

參考答案:

正確

Besidesionexchangecolumnchromatography,otherchromatographytechniquesinclude().

參考答案:

Affinitychromatography:Substancesbindtothespecificgroupsoftheresinwithdifferentaffinities._Hydrophobicchromatography:Substanceshavedifferentaffinitiestothehydrophobicgroupscoupledwiththeresin._IsoelectricFocusing:Thedifferenceinisoelectricpointamongtheseparatedsubstances.Itisbasedontheisoelectricpointdifferenceofseparatedcomponents._Gelfiltrationchromatography:Itisbasedonthemolecularweightdifferenceofseparatedcomponents.

Regardingthepreparationofcaseininmilk,whichofthefollowingstatementiscorrect().

參考答案:

GlacialaceticacidisusedtoadjustthepHofmilk.ProteinwillprecipitateifthepHofthesolventisnearitsisoelectricpoint._Somewheyproteinswillalsoprecipitateoutwhileheated._Inthepurificationofcasein,differentrinsingsolventsisusedinsequence.

WhenusingCoomassieBrilliantBluemethodtomeasureproteins,whichofthefollowingfactorswillinterferewiththeresults?()

參考答案:

TritonX-100

BesidesCoomassieBrilliantBluemethod,()methodscanalsobeusedtodetermineproteinsconcentration.

參考答案:

Folin-phenolreagentmethod(Lowrymethod)_Biuretmethod_Kjeldahlmethod_Ultravioletabsorptionmethod

WhenusingtheCoomassiebrilliantbluemethodtodetermineprotein,theproteincontentofthesampleshouldbe10-100μg.()

參考答案:

正確

TheisoelectricpointofimmunoglobulininserumismostlyaroundpH7.Forexample,pIofIgMis7.0andpIofIgAis7.4.AftercelluloseacetatemembraneelectrophoresisusingpH8.6barbituratesodiumelectrodebuffer,whichregionwillthesetwoproteinslocateat?()

參考答案:

nearγ-globulin

Aftertheproteinbandisleachedbytheleachingsolution,itisquantifiedbycolorimetricmethodat______nm.

參考答案:

590

Thesampleshouldbeboiledfor10minutesbeforeloading.()

參考答案:

正確

ToquantifyDNAwiththediphenylaminecolorimetricmethod,theabsorbancevalueshouldbemeasuredat______nm.

參考答案:

595

Yeast(Saccharomyce),oneoftheprokaryoticmodels,iscommonlyappliedingenecloningexperiment.()

參考答案:

錯(cuò)誤

Inthepresentexperiment,theforefrontbandatabout100bpobservedunderultravioletlightis______.

參考答案:

ResidualRNA

Accordingtothehydrolyticcharacteristics,catalyticconditionsandmodificationcapacity,restrictionenzymescouldbedividedinto().

參考答案:

TypeI_TypeIII_TypeII

WhichofthefollowingfactorsarerelatedtoKm?()

參考答案:

Enzymespecies_Substratespecies

Trichloroaceticacidisastrongacidwhichcanacceleratetheenzymereactionbydenaturingenzymeprotein.()

參考答案:

錯(cuò)誤

Thestandardcarbohydratesolutionusedinthisexperimentis().

參考答案:

0.1mg/mLglucosesolution

WhatistheunitofKm?()

參考答案:

mol/L

ThepHofSDSelectrophoresisbufferis().

參考答案:

8.3

Whichofthefollowingmethodisbasedonthechargedifferencecarriedbythechargedmoleculestoseparatediversesubstances?()

參考答案:

Ionexchangechromatography

Whichofthefollowingstatementiswrong().

參考答案:

ThedissociableOH-ofthecationexchangeresincouldexchangewithcationsinthesolutionphase.

Whichofthefollowingmethoddoesnotconsumeproteinsamples,andtheproteincanstillberecycledaftermeasurement().

參考答案:

Ultravioletabsorptionmethod

Themostabundantproteininmilkis().

參考答案:

Casein

Whichfollowingsubstancescannotbeusedaslipidextractionsolvents().

參考答案:

water

Whataretherolesof25%sulfuricacidintheexperiment?()

參考答案:

ProvidetheacidicenvironmentrequiredforKMnO?titration._Denatureenzymetostoptheenzymaticreaction.

RegardingtheextractionstepsofanimalliverDNA,whichofthefollowingstatementsarecorrect?()

參考答案:

NaClpowdershouldbeaddedinbatchesandshakenasitisaddedtoavoidhighlocalsaltconcentration._DNAextractionprocessshouldavoidexcessiveacid,alkali,hightemperatureanddamagebymechanicaltension.

DuringDNAextraction,chloroform-isoamylalcoholandSDSareadded.Aftercentrifugation,thelayersareshowsinthefigure.Whichofthefollowingstatementsarecorrect?()

參考答案:

TheupperlayerisanaqueousphasecontainingDNA,themiddlelayerisdenaturedproteins,andthelowerlayerischloroform._SDScandestroytheadvancestructureofproteinsandcausetheproteinstodissociatefromDNA._Chloroformisaproteinsdenaturant,whichcanprecipitateproteinandacceleratetheseparationoforganicphaseandaqueousphase.

Afteraddingtheseparatinggelsolutionintothegapbetweentwoglassplates,itisnecessarytocovertheseparatinggelwithalayerofwaterimmediately.Thepurposeofthisoperationis().

參考答案:

preventingoxygenfromdiffusingintothegelandinterferingwithpolymerization_eliminatingbubbles

Whatfactorsshouldbeconsideredinthemethodsselectionofproteinconcentrationdetermination?()

參考答案:

Interferingsubstancespresentinthesolution_Thesensitivityandaccuracyrequiredintheexperiment_Thepropertiesoftheanalyzedprotein_Thetimeittakestodeterminetheproteinconcentration

Whichofthefollowingindicatorsareusedtomeasurethefreshnessoflipid?()

參考答案:

Malonaldehydevalue_Acidvalue_Peroxidevalue

Naturalplasmidsarecircularsingle-strandedDNA.()

參考答案:

錯(cuò)誤

DNA-bindingproteins(DNP)existsinthenucleusandisslightlysolubleinhighsaltsolution(1mol/L)andsolubleinlowsaltsolution(0.14mol/L).()

參考答案:

錯(cuò)誤

InSDS,reducingsubstancesareusedtobreakdisulfidebonds.Therefore,themolecularweightsofthesubunitsorsinglechainswillbeactuallymeasured.()

參考答案:

正確

Celluloseacetatemembraneelectrophoresishaslowerresolutionthanpolyacrylamidegelelectrophoresis(PAGE)inproteinsseparation.()

參考答案:

正確

Bypretreatmentoffreshresin,theimpurities,suchasresidualsolvents,oligomersandafewheavymetalions(suchasFe3+,Cu2+),couldberemoved()

參考答案:

正確

Caseiniswhiteandodorless.Itisinsolubleinwaterandorganicsolventssuchasethanol,butsolubleinalkalinesolutions.()

參考答案:

正確

Inthisexperiment,concentratedhydrochloricacidcouldbeusedinsteadofglacialaceticacidtoadjustpH.()

參考答案:

錯(cuò)誤

Afterextraction,thesmallflaskcontainingthecrudelipidssampleisdriedat103-105°Cfor30min.Becarefulnottooverheat.()

參考答案:

正確

Theheatinginstrumentusedfortheextractionofcrudelipidsis______.

參考答案:

thermostatwaterbath

SDSgelisdividedintoupperandlowerparts,thelowerpartiscalled______.

參考答案:

separatinggel

Accordingtothedifferentnumbersofaminoandcarboxylgroupscontainedinaminoacids,aminoacidsaredividedintothreecategories:acidicaminoacids,______aminoacidsandbasicaminoacids.

參考答案:

neutral

Afteraddingtheanthronereagent,solventsneedtobeaccuratelyheatedinaboilingwaterbathfor______minutestocompletethereaction.

參考答案:

10

Kmvaluereflectstheaffinitybetweentheenzymeandthesubstrate.ThelargertheKmvalueis,theweakertheaffinitywillbe.Onthecontrary,thesmallertheKmvalueis,thestrongertheaffinitywillbe.()

參考答案:

正確

Trypsinisaserineproteolyticenzymeextractedfromthepancreasofcattles,sheepsandpigs.Itcandigestthepeptidebondformedbythecarboxylgroupsofarginineandlysineresiduesinthepolypeptidechain.()

參考答案:

正確

Theconcentrationofsulfuricacidusedtopreparetheanthronereagentis().

參考答案:

80%

Thisexperimentisusedtodeterminethe()contentinplants.

參考答案:

totalsolublecarbohydrate

Anthronecolorimetricassaycouldbeusedtodeterminewhichofthefollowingsubstances?()

參考答案:

starch_fructose_monosaccharide_glycogen

Beforeaddingtheanthronereagent,thetesttubeshouldbecooledinanicewaterbath.()

參考答案:

正確

Carbohydrateisdehydratedbytheconcentratedsulfuricacidtoproducefurfuralorhydroxymethylfurfural.Furfuralorhydroxymethylfurfuralcanreactwith______toproducesomeblue-greenfurfuralderivatives.

參考答案:

anthrone

WhichofthefollowingaminoacidswillproducemorethanoneDNS-modifiedproducts?()

參考答案:

His_Tyr_Lys

TheroleofI2-KIsolutionis().

參考答案:

Indicatingwhethertheextractiscompletelyhydrolyzed.Thecompletedhydrolysissolutiondoesnotturnblue.

Whenmeasuringthecontentofreducingcarbohydrateby3,5-dinitrosalicylicacidmethod,thewavelengthis()nm.

參考答案:

540

Whichofthefollowingstatementsaboutthisexperimentarecorrect?()

參考答案:

Totalcarbohydrateincludesreducingcarbohydrateandnon-reducingcarbohydrate._Whendeterminingthetotalcarbohydrateinthisexperiment,itisnecessarytofirstlyhydrolyzethetotalcarbohydratetoreducingcarbohydrateunderacidicconditions._Reducingcarbohydrateisreductiveandcontainfreealdehydegroupsorketonegroups.

Additionofsodiumsulfitetothe3,5-dinitrosalicylicacidreagentcouldeliminatetheinfluenceofdissolvedoxygeninthereagentandstabilizethereagent.()

參考答案:

正確

Whichfollowingsubstancescannotbeusedaslipidextractionsolvents().

參考答案:

water

TheSoxhletextractionusedinthisexperimentisbasedon().

參考答案:

gravimetricanalysismethod

Whichofthefollowingsubstancesbelongtocrudefat?()

參考答案:

freefattyacid_sterol_pho