BCH5413 - Exam 3 Questions And Answers

BCH5413 - Exam 3 Questions And
Answers
3tbreakpointstintBcrtaretobservedtintchromosomalttranslocationstintdifferentttypestoftleukem
iast-tCORRECTttANSWER-ALL,tCML,tandtCNL

3tkeytmembrane-associatedtcomponentstintGPCRtsignalingt-tCORRECTttANSWER-
1.treceptorst(GPCR)
2.theterotrimerictGtproteins
3.teffectortproteins

Atmajoritytoftp53tmutationstinthumantcancerstaretwhatttypetoftmutationt-
tCORRECTttANSWER-missensetpoint

-tthetvasttmajoritytaffecttthetDNAtbindingtdomain

Atmutationtis..t-tCORRECTttANSWER-atchangetintthetnormaltsequencetoftDNA

Activatedtmitotictcyclin-cdktmaintaintthetactivetstatetbytregulatingtbotht__andt__t-
tCORRECTttANSWER-Wee1tandtCdc25

*havetoppositeteffectstontmitotictcdktactivity

ActivatingtMutationstintSrctFamilytKinasest-tCORRECTttANSWER--tSrctistatnon-
receptorttyrosinetkinase
-tnormaltSrctproteinstaretinactivatedtwhentTyrtistphosphorylatedtbytCsk
-tactivatingtmutationstresulttintSrctoncoproteintlackingtthetinhibitorytphosphorylationtsite
-tviraltSrctlackstc-terminaltTyrtsitetandtistconstitutivelytactive

Activationtoftacetylcholinetreceptort(GPCR)tandtitsteffectortK+tchannelt-
tCORRECTttANSWER--tbindingtoftacetylcholinettotitstreceptortactivatestG-alpha-

itandtdissociatestittfromtG-betatgamma
-tthetreleasedtG-betatgammatsubunitt(rathertthantG-alpha-
i)tbindsttottheteffectortprotein:tatK+tchannel,tandtopenstit

ActivationtoftCREBttranscriptiontfactortfollowingtligandtbindingttotGPCR'st-
tCORRECTttANSWER--tligandtbindingttotGPCRtactivatestG-

alphatandtadenylyltcyclasettotproducetcAMP

,-
tcAMPtbindsttotandtactivatestPKA.tCatalytictsubunitstoftPKAttranslocatetintotnucleustandtph

osphorylatettranscriptiontfactortCREB
-tphosphorylatedtCREBtrecruitstcoactivatortp300/CBPttotstimulatettargettgenettranscription

Activationtoftmitotictcdk
-tundertwhattcircumstancestdoestassociationtwithtcdktoccur
-twhattinhibitstcdktactivity
-twhattactivatestcdktactivityt-tCORRECTttANSWER--
tmitotictcyclintlevelstrise,tassociatetwithtmitotictcdkt(partiallytactive)

-tWee1tphosphorylatestmitotictcdkttyrosinetY15tinhibitingtactivity
-
tCAKtphosphorylatestmitotictcdktthreoninet161tactivatingtsite.tButtwhentY15tistphosphorylat

ed,tmitotictcdktremainstinactive
-tmitotictcyclin-
cdktcantbetactivatedtonlytaftertcdc25tremovestphosphatetfromtinhibitorytsitet(Y15)twhiletpho
sphorylationtoftactivetsitetistmaintainedt(CKItmusttalsotbetremoved)

ActivationtoftPKAtbytcAMPt-tCORRECTttANSWER--
tPKAthasttwotregulatorytsubunitstandt2tcatalytictsubunits

-
twhentcAMPtbindsttotthetregulatorytsubunitst(eachtregulatorytsubunittbindst2tcAMPtmolecul

es),tthetcatalytictsubunitstaretreleasedtandtactivated

ActivationtoftPKCtbytDAGtandtIP3t-tCORRECTttANSWER--
tligandtbindingttotGPCRtactivatestG-alphatleadingttotactivationtoftPLC

-tPLCtcleavestPIP2ttotgeneratetDAGtandtIP3
-tIP3tdiffusestintotcytosol,tbindsttotopentCa++tchannelstandtimportstCa++tintotthetcytosol
-
televatedtcytosolictCa++trecruitstPKCttotthetplasmatmembrane,twheretittistactivatedtbytDAG

-tactivatedtPKCtphosphorylatestdownstreamtsubstrates

ActivationtoftRastfollowingtligandtbindingttotRTK's
-tGTP-boundtRastis...
-thydrolysist-tCORRECTttANSWER-GTP-boundtRastistfunctional
-thydrolysistoftGTPtbytRastistfacilitatedtbytGAPtwhichtleadsttotGDP-
boundtRas,twhichtistinactive

ActivationtoftRastfollowingtligandtbindingttotRTK's
-tRastistfrequentlytactivatedtby...t-tCORRECTttANSWER-mutationtintcancer

ActivationtoftRastfollowingtligandtbindingttotRTK's
-twhattistRast-tCORRECTttANSWER-Rastistatsmall,tmonomerictGtprotein

ActivationtoftRTKtproto-oncogenes

,-t2twayst-tCORRECTttANSWER-
1.tpointtmutationtintHer2ttransmembranetdomaintcausestreceptortdimerizationtconstitutivel
ytactivatingtthetreceptor

2.tatmutationtcausestdeletiontoftEGFRtextracellulartdomains,tleadingttotreceptortdimerizatio
ntandtactivationtwithouttatligand

Alkylatingtagentstaddtalkyltgroupstto...t-tCORRECTttANSWER-bases

AllosterictactivationtoftligandstbindingttotGPCRt-tCORRECTttANSWER-
ligandtbindingttotGPCRtcausestallosterictconformationaltchangestintcytosolictdomainstoftth
etreceptor,tleadingttotrecruitmenttoftGtproteins

Alteredtglucosetmetabolismtintcancert-tCORRECTttANSWER-Normaltcell
-toxidativetmetabolismt

Cancertcell
-taerobictglycolysis
-tresultstintproliferationtandtmetastasistchemoresistance

ALVtandtc-myc
-tacutetandtslowttransformingtvirust-tCORRECTttANSWER-Acutettransforming
-teverytinfectedtcelltexpressestthetviraltoncogenet(rapidttumortformation)

Slowttransforming
-tonlytraretinfectedtcellstactivatetcellulartproto-oncogenestbytinsertiont(lowttumorigenicity)

ALVtandtc-Myc
-thowtittworkst-tCORRECTttANSWER-ALVtprovirustsometimestinsertstadjacentttotc-
myctproto-oncogenetandtthetALVtpromotertstronglytinducestc-myctexpression
-tthistexpressiontdrivestcelltproliferationtandtarettransformed

Anaphase:twhattoccurstconcerningtAPC,tchromatids,tspindletmicrotubulest-
tCORRECTttANSWER--tAPCtistactivatedtandtdegradestcohesinet

-tAPCtallowstsistertchromatidsttotseparate
-
tshorteningtoftspindletmicrotubulestpullstseparatedtsistertchromatidsttowardtoppositetsidest

oftthetcell

APCtandtanaphase-telophasettransitiont-tCORRECTttANSWER-intlatetanaphase,tAPC-
cdh1tdestructstmitotictcyclin,tthustinactivatingtmitotictcdktandttriggeringtentrytintottelophase

APCtistatwhat..t-tCORRECTttANSWER-E3tubiquitintligase

Arettheretmoretnon-codingtRNA'stortgenest-tCORRECTttANSWER-non-codingtRNAs

, Arettumortcellstpure?t-tCORRECTttANSWER-NO
-ttumortcellstfromtdifferenttareastaretdifferent

Arraytcomparativetgenomicthybridizationt(aCGH)
-twhattdoestittmeasuret-tCORRECTttANSWER-
measurementtoftgenetcopytnumbertinttumortsamples
-tgenometwidetdetectiontoftamplificationtand/ortdeletion

*strengthtoftfluorescenttsignalstcorrelatesttotgenetcopytnumber

BasetExcisiontRepairt(BER)toftatT-Gtmismatch
-tstepst-tCORRECTttANSWER-1.tspecifictDNAtglycosylasetrecognizestT-
Gtmismatch,tremovestTtfromthelix,tbreakstglycosidictbond,tandtclipstouttthetwrong/damage
dtbase.tThistleadsttotantAPtsitet

2.tAntAPtendonucleaset(APE1)trecognizestthetAPtsite,tnickstthetDNAtstrandtontitst5'tside

3.tAtlyasetremovestthethangingtdeoxyribosetphosphate

4.tDNAtPol-betatfillstintthetgaptwithtatnormaltnucleotidet(C)tandtDNAtligasetsealstthetnick

Becausetcelltcycletregulatorstarethighlytconserved,t____tcantoftentrescuetyeasttcdctmutant
st-tCORRECTttANSWER-humantcDNA's

Bindingtoftcdh1ttotAPCtistregulatedtby..t-tCORRECTttANSWER-phosphorylation
-tG1tcyclin-cdktinhibitstCdh1
-tphosphatasaetcdc14tactivatestcdh1

BishoptandtVarmustdiscoveryt-tCORRECTttANSWER-hosttcellsthavetSrc-
relatedtsequences

BRCA-deficienttcancertcellstaretdefectivetin...t-tCORRECTttANSWER-
Homologoustrecombination

BRCA1t+tBRCA2t+tRad51
-twhattittdoest-tCORRECTttANSWER-promoteststrandtinvasiontandtDtlooptformation
-tplaytatkeytroletintthethomologoustrecombinationtprocesstandtrepairtoftdamagedtDNA

BRCA1/2tandtgenometintegrityt-tCORRECTttANSWER--
tBRCA1tproteintistatmultifunctionaltnucleartproteintinvolvedtintDNAtrepair,tcelltcycletregulati

on,ttranscriptionaltcontrol,tchromatintremodeling

-tBRCA2tfunctionstontdoubletstrandtbreaktrepair

BRCA1/2:tsynthetictlethalitytwithtPARP1tinhibition
-ttwotgenestaretsynthetictlethaltif...