BCH Final Exam Set Questions And
Answers
______risrtherfirstrcompoundrthatrisroxidizedrinrthercitricracidrcycle.r-rCORRECTrrANSWER-
Isocitrate
"Energyrcharge"rinrarcellrisrarmeasurerofr-rCORRECTrrANSWER-ATP/ADPrratios.
ArbiochemistrisrattemptingrtorseparaterarDNA-
bindingrproteinr(proteinrX)rfromrotherrproteinsrinrarsolution.rOnlyrthreerotherrproteinsr(A,rB,ra
ndrC)rarerpresent.rTherproteinsrhavertherpropertiesrlistedrinrthertablerbelow.rWhatrtyperofrpro
teinrseparationrtechniquermightrberusedrtorseparaterproteinrXrfromrproteinrA?
ProteinrpIrMWr(kDa)rBindrtorDNA?rAr7.4r82ryesrBr3.8r21.5ryesrCr7.9r23rnorXr7.8r22ryesr-
rCORRECTrrANSWER-Size-exclusionrchromatography
Argivenrreactionroccursrspontaneously,rwithranrexothermicrchangerinrenthalpyrandranrincre
aserinrdisorder.rWhichranswerrchoicerbelowrcorrectlyrassignsrtherrelativerchangesrtorΔS,rΔ
H,randrΔG?r-rCORRECTrrANSWER-+)ΔS;r(-)ΔH;randr(-)ΔG
Armajorrdifferencerbetweenramyloserandramylopectinrisrthatr-rCORRECTrrANSWER-
amylopectinrisrbranchedrandramyloserisrnot.
Arpalindromerisr-rCORRECTrrANSWER-
arsequencerthatrreadsrthersamerfromrleftrtorrightrorrfromrrightrtorleft
Arreactionrwillrberspontaneousratrallrtemperaturesrifrwhatrtworconditionsrarermet?r-
rCORRECTrrANSWER-ardecreaserinrenthalpyrandrincreaserinrentropy
ArresearcherrisolatesrmutantrvariantsrofrtherbacterialrtranslationrfactorsrIF2,rEF-Tu,randrEF-
G.rInreachrcase,rthermutationrallowsrproperrfoldingrofrtherproteinrandrtherbindingrofrGTP,rbutr
doesrnotrallowrGTPrhydrolysis.rAtrwhatrstagerwouldrtranslationrberblockedrbyrthermutantrIF2
rprotein?r-rCORRECTrrANSWER-
Therfullrinitiationrcomplexrwouldrformrbutrinitiationrfactorsrwouldrnotrberreleasedrandrelongat
ionrcouldrnotrstart.
Arsacchariderthatrhasrfreeraldehydergrouprisrcalledra(n)r_____________.r-
rCORRECTrrANSWER-reducingrsugar
, Activationroframinoracidsr-rCORRECTrrANSWER-producesrarpyrophosphaterbyproduct.
AdvantagesrofrtherPolymeraserChainrReactionrincluderallrofrthese,rexcept:r-
rCORRECTrrANSWER-AllrofrtheserareradvantagesrofrPCR.
Afterrtherfollowingrfeaturesrarercommonrtorallrlivingrorganisms,rexcept:r-
rCORRECTrrANSWER-cellularrstructures
Anrenzymercatalyzesrarreactionratrarvelocityrofr20rμmol/minrwhenrtherconcentrationrofrsubst
raterisr0.01rM.rTherKMrforrthisrsubstraterisr1rxr10-5rM.rAssumingrthatrMichaelis-
Mentenrkineticsrarerfollowed,rwhatrwillrtherreactionrvelocityrberwhenrtherconcentrationrofrsu
bstraterisr1rxr10-5rM?r-rCORRECTrrANSWER-10rμmol/min
AnrenzymerhasrarKMrofr3rmMrinrtherabsencerofrarcompetitiverinhibitorrinrarsolutionrofr2rmMrs
ubstraterandrarVmaxrofr15rnM/s.rWhatrconcentrationrofrarcompetitiverinhibitorrwithrKIrofr3rm
Mrisrrequiredrtorachieveranrinitialrvelocityrofr5rnM/s?r-rCORRECTrrANSWER-
1.0rmicromolarr(mM)
BasedronrtherfollowingrTmrvalues,rwhatrcanrbersaidraboutrthesertworDNArmolecules:rStrand
rAr=r80°C;rStrandrBr=r100°C?r-rCORRECTrrANSWER-
StrandrArhasrarhigherrpercentagerofradeninerbases,rstrandrBrhasrarhigherrpercentagerofrcyt
osinerbases,randrstrandrBrhasrstrongerrstackingrinteractions.
Basedronrtherreactionrbelow,rhowrwouldrtherenzymercatalyzingrthisrreactionrberclassified?r-
rCORRECTrrANSWER-Isomerase
Berberirisrardiseaserthatrresultsrfromrardietaryrlackrofrthiamine,rthervitaminrthatrservesrasrarpr
ecursorrforrthiaminerpyrophosphater(TPP).rWhichrmetabolite(s)raccumulaterinrindividualsr
withrberiberi,respeciallyrafterringestionrofrglucose?r-rCORRECTrrANSWER-pyruvaterandrα-
ketoglutarate
Branchingrandrdebranchingrenzymesrusertherexactrsamermechanismrtoraddrandrremoverth
erbranchesrofrtherglycogenrpolymer.r-rCORRECTrrANSWER-False
Certainrrestrictionrenzymesrproducercohesiver(sticky)rends.rThisrmeansrthatrthey:r-
rCORRECTrrANSWER-makerarstaggeredrdouble-
strandrcut,rleavingrendsrwithrarfewrnucleotidesrofrsingle-strandedrDNArprotruding.
Chainrterminationroccurs,rinrvivo,rwhen:r-rCORRECTrrANSWER-
Eitherrarhairpinrlooprformsrorrrhor(ρ)rcatchesruprwithrtranscriptionrstalledrbyrarhairpinrloop.
Cholesterolrisrparticularlyrimportantrasrarcomponentrofranimalrmembranes.r-
rCORRECTrrANSWER-True
Answers
______risrtherfirstrcompoundrthatrisroxidizedrinrthercitricracidrcycle.r-rCORRECTrrANSWER-
Isocitrate
"Energyrcharge"rinrarcellrisrarmeasurerofr-rCORRECTrrANSWER-ATP/ADPrratios.
ArbiochemistrisrattemptingrtorseparaterarDNA-
bindingrproteinr(proteinrX)rfromrotherrproteinsrinrarsolution.rOnlyrthreerotherrproteinsr(A,rB,ra
ndrC)rarerpresent.rTherproteinsrhavertherpropertiesrlistedrinrthertablerbelow.rWhatrtyperofrpro
teinrseparationrtechniquermightrberusedrtorseparaterproteinrXrfromrproteinrA?
ProteinrpIrMWr(kDa)rBindrtorDNA?rAr7.4r82ryesrBr3.8r21.5ryesrCr7.9r23rnorXr7.8r22ryesr-
rCORRECTrrANSWER-Size-exclusionrchromatography
Argivenrreactionroccursrspontaneously,rwithranrexothermicrchangerinrenthalpyrandranrincre
aserinrdisorder.rWhichranswerrchoicerbelowrcorrectlyrassignsrtherrelativerchangesrtorΔS,rΔ
H,randrΔG?r-rCORRECTrrANSWER-+)ΔS;r(-)ΔH;randr(-)ΔG
Armajorrdifferencerbetweenramyloserandramylopectinrisrthatr-rCORRECTrrANSWER-
amylopectinrisrbranchedrandramyloserisrnot.
Arpalindromerisr-rCORRECTrrANSWER-
arsequencerthatrreadsrthersamerfromrleftrtorrightrorrfromrrightrtorleft
Arreactionrwillrberspontaneousratrallrtemperaturesrifrwhatrtworconditionsrarermet?r-
rCORRECTrrANSWER-ardecreaserinrenthalpyrandrincreaserinrentropy
ArresearcherrisolatesrmutantrvariantsrofrtherbacterialrtranslationrfactorsrIF2,rEF-Tu,randrEF-
G.rInreachrcase,rthermutationrallowsrproperrfoldingrofrtherproteinrandrtherbindingrofrGTP,rbutr
doesrnotrallowrGTPrhydrolysis.rAtrwhatrstagerwouldrtranslationrberblockedrbyrthermutantrIF2
rprotein?r-rCORRECTrrANSWER-
Therfullrinitiationrcomplexrwouldrformrbutrinitiationrfactorsrwouldrnotrberreleasedrandrelongat
ionrcouldrnotrstart.
Arsacchariderthatrhasrfreeraldehydergrouprisrcalledra(n)r_____________.r-
rCORRECTrrANSWER-reducingrsugar
, Activationroframinoracidsr-rCORRECTrrANSWER-producesrarpyrophosphaterbyproduct.
AdvantagesrofrtherPolymeraserChainrReactionrincluderallrofrthese,rexcept:r-
rCORRECTrrANSWER-AllrofrtheserareradvantagesrofrPCR.
Afterrtherfollowingrfeaturesrarercommonrtorallrlivingrorganisms,rexcept:r-
rCORRECTrrANSWER-cellularrstructures
Anrenzymercatalyzesrarreactionratrarvelocityrofr20rμmol/minrwhenrtherconcentrationrofrsubst
raterisr0.01rM.rTherKMrforrthisrsubstraterisr1rxr10-5rM.rAssumingrthatrMichaelis-
Mentenrkineticsrarerfollowed,rwhatrwillrtherreactionrvelocityrberwhenrtherconcentrationrofrsu
bstraterisr1rxr10-5rM?r-rCORRECTrrANSWER-10rμmol/min
AnrenzymerhasrarKMrofr3rmMrinrtherabsencerofrarcompetitiverinhibitorrinrarsolutionrofr2rmMrs
ubstraterandrarVmaxrofr15rnM/s.rWhatrconcentrationrofrarcompetitiverinhibitorrwithrKIrofr3rm
Mrisrrequiredrtorachieveranrinitialrvelocityrofr5rnM/s?r-rCORRECTrrANSWER-
1.0rmicromolarr(mM)
BasedronrtherfollowingrTmrvalues,rwhatrcanrbersaidraboutrthesertworDNArmolecules:rStrand
rAr=r80°C;rStrandrBr=r100°C?r-rCORRECTrrANSWER-
StrandrArhasrarhigherrpercentagerofradeninerbases,rstrandrBrhasrarhigherrpercentagerofrcyt
osinerbases,randrstrandrBrhasrstrongerrstackingrinteractions.
Basedronrtherreactionrbelow,rhowrwouldrtherenzymercatalyzingrthisrreactionrberclassified?r-
rCORRECTrrANSWER-Isomerase
Berberirisrardiseaserthatrresultsrfromrardietaryrlackrofrthiamine,rthervitaminrthatrservesrasrarpr
ecursorrforrthiaminerpyrophosphater(TPP).rWhichrmetabolite(s)raccumulaterinrindividualsr
withrberiberi,respeciallyrafterringestionrofrglucose?r-rCORRECTrrANSWER-pyruvaterandrα-
ketoglutarate
Branchingrandrdebranchingrenzymesrusertherexactrsamermechanismrtoraddrandrremoverth
erbranchesrofrtherglycogenrpolymer.r-rCORRECTrrANSWER-False
Certainrrestrictionrenzymesrproducercohesiver(sticky)rends.rThisrmeansrthatrthey:r-
rCORRECTrrANSWER-makerarstaggeredrdouble-
strandrcut,rleavingrendsrwithrarfewrnucleotidesrofrsingle-strandedrDNArprotruding.
Chainrterminationroccurs,rinrvivo,rwhen:r-rCORRECTrrANSWER-
Eitherrarhairpinrlooprformsrorrrhor(ρ)rcatchesruprwithrtranscriptionrstalledrbyrarhairpinrloop.
Cholesterolrisrparticularlyrimportantrasrarcomponentrofranimalrmembranes.r-
rCORRECTrrANSWER-True
