Test bank biochemistry test 1

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1. TheMdipoleMmomentMinMaMwaterMmoleculeMWhichMstatementMaboutMhydrogenMbondsMisM
NOTMtrue?
A) HydrogenMbondsMaccountMforMtheManomalouslyMhighMboilingMpointMofMwater.
B) InMliquidMwater,MtheMaverageMwaterMmoleculeMformsMhydrogenMbondsMwithMthre
eMtoMfourMotherMwaterMmolecules.
C) IndividualMhydrogenMbondsMareMmuchMweakerMthanMcovalentMbonds.
D) IndividualMhydrogenMbondsMinMliquidMwaterMexistMforMmanyMsecondsMandMsometi
mesMforMminutes.
E) TheMstrengthMofMaMhydrogenMbondMdependsMonMtheMlinearityMofMtheMthreeMat
omsMinvolvedMinMtheM bond.


2. AMTRUEMstatementMaboutMhydrophobicMinteractionsMisMthatMthey:
A) areMtheMdrivingMforceMinMtheMformationMofMmicellesMofMamphipathicMcompound
sMinMwater.
B) doMnotMcontributeMtoMtheMstructureMofMwater-solubleMproteins.
C) haveMbondingMenergiesMofMapproximatelyM20–40MKjouleMperMmole.
D) involveMtheMabilityMofMwaterMtoMdenatureMproteins.
E) primarilyMinvolveMtheMeffectMofMpolarMsolutesMonMtheMentropyMofMaqueousMsystems.



3. HydrophobicMinteractionsMmakeMimportantMenergeticMcontributionsMto:
A) bindingMofMaMhormoneMtoMitsMreceptorMprotein.
B) enzyme-substrateMinteractions.
C) membraneMstructure.
D) three-dimensionalMfoldingMofMaMpolypeptideMchain.
E) AllMofMtheManswersMareMcorrect.



4. DissolvedMsolutesMalterMsomeMphysicalM(colligative)MpropertiesMofMtheMsolventMw
aterMbecauseMtheyMchangeMthe:
A) concentrationMofMtheMwater.
B) hydrogenMbondingMofMtheMwater.
C) ionicMbondingMofMtheMwater.
D) pHMofMtheMwater.



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E) temperatureMofMtheMwater.



5. OsmosisMisMmovementMofMa:
A) chargedMsoluteMmoleculeM(ion)MacrossMaMmembrane.
B) gasMmoleculeMacrossMaMmembrane.
C) nonpolarMsoluteMmoleculeMacrossMaMmembrane.
D) polarMsoluteMmoleculeMacrossMaMmembrane.
E) waterMmoleculeMacrossMaMmembrane.



6. AMhydroniumMion:
A) hasMtheMstructureMH3O+.
B) isMaMhydratedMhydrogenMion.
C) isMaMhydratedMproton.
D) isMtheMusualMformMofMoneMofMtheMdissociationMproductsMofMwaterMinMsolution.
E) AllMofMtheManswersMareMcorrect.



7. TheMpHMofMaMsolutionMofM1MMMHClMis:
A) 0.
B) 0.1.
C) 1.
D)MMM 10.
E) –1.



8. TheMpHMofMaMsolutionMofM0.1MMMNaOH
Mis:M
A)M 0.1.
B) 1.0.
C) 12.8.
D)MMM 13.
E) 14.




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9. WhichMstatementMisMTRUEMaboutMtheMpropertiesMofMaqueousMsolutions?
A) AMpHMchangeMfromM5.0MtoM6.0MreflectsManMincreaseMinMtheMhydroxideMionMconcentra
tionM([OH–])MofM20%.
B) AMpHMchangeMfromM8.0MtoM6.0MreflectsMaMdecreaseMinMtheMprotonMconcentrationM([
H+])MbyMaMfactorMofM100.
C) ChargedMmoleculesMareMgenerallyMinsolubleMinMwater.
D) HydrogenMbondsMformMreadilyMinMaqueousMsolutions.
E) TheMpHMcanMbeMcalculatedMbyMaddingM7MtoMtheMvalueMofMtheMpOH.



10. TheMpHMofMaMsampleMofMbloodMisM7.4,MwhileMgastricMjuiceMisMpHM1.4.M TheMbloodMsampleMhas:
A) 0.189MtimesMtheM[H+]MasMtheMgastricMjuice.
B) 5.29MtimesMlowerM[H+]MthanMtheMgastricMjuice.
C) 6MtimesMlowerM[H+]MthanMtheMgastricMjuice.
D) 6000MtimesMlowerM[H+]MthanMtheMgastricMjuice.
E) oneMmillionMtimesMlowerM[H+]MthanMtheMgastricMjuice.



11. TheMaqueousMsolutionMwithMtheMLOWESTMpHMis:
A) 0.01MMMHCl.
B) 0.1MMMaceticMacidM(pKaM=M4.86).
C) 0.1MMMformicMacidM(pKaM=M3.75).
D) 0.1MMMHCl.
E) 10–12MMMNaOH.



12. TheMaqueousMsolutionMwithMtheMHIGHESTMpHMis:
A) 1MMMHCl.
B) 1MMMNH3M(pKaM=M9.25).
C) 0.5MMMNaHCO3M(pKaM=M3.77).
D) 0.1MMMNaOH.
E) 0.001MMMNaOH.




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13. PhosphoricMacidMisMtribasic,MwithMpKa'sMofM2.14,M6.86,MandM12.4.MTheMionicMform
MthatM
predominatesMatMpHM3.2Mis:
A) H3PO4.
B) H2PO4–.
C) HPOM42–.
D) POM4 3–.
E) NoneMofMtheManswersMisMcorrect.



14. WhichMstatementMaboutMbuffersMisMTRUE?
A) AMbufferMcomposedMofMaMweakMacidMofMpKaM=M5MisMstrongerMatMpHM4MthanMatMpHM6.
B) AtMpHMvaluesMlowerMthanMtheMpKa,MtheMsaltMconcentrationMisMhigherMthanMthatMo
fMtheMacid.
C) TheMpHMofMaMbufferedMsolutionMremainsMconstantMnoMmatterMhowMmuchMacidMorMba
seMisMaddedMtoMtheMsolution.
D) TheMstrongestMbuffersMareMthoseMcomposedMofMstrongMacidsMandMstrongMbases.
E) WhenMpHM=MpKa,MtheMweakMacidMandMsaltMconcentrationsMinMaMbufferMareMequal.



15. AMcompoundMhasMaMpKaMofM7.4.M ToM100MmLMofMaM1.0MMMsolutionMofMthisMcompoundMatMpH
8.0MisMaddedM30MmLMofM1.0MMMhydrochloricMacid.MTheMresultingMsolutionMisMp
H:MA)M 6.5.
B) 6.8.
C) 7.2.
D)MMM 7.4.
E) 7.5.



16. TheMHenderson-HasselbalchMequation:
A) allowsMtheMgraphicMdeterminationMofMtheMmolecularMweightMofMaMweakMacidMfro
mMitsMpHMalone.
B) doesMnotMexplainMtheMbehaviorMofMdi-MorMtri-basicMweakMacids.
C) employsMtheMsameMvalueMforMpKaMforMallMweakMacids.
D) isMequallyMusefulMwithMsolutionsMofMaceticMacidMandMofMhydrochloricMacid.
E) relatesMtheMpHMofMaMsolutionMtoMtheMpKaMandMtheMconcentrationsMofMacidMandMconj
ugateMbase.




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