Biolghn253ghnExamghn1
universalghnfunctionghnofghnmembranesghn-
ghnCORRECTghnANSWER✔toghnactghnasghnaghnselectiveghnbarrierghntoghntheghnpa
ssageghnofghnmolecules
functionsghnofghnplasmaghnmembranesghn-
ghnCORRECTghnANSWER✔1.ghnregulateghnpassageghnofghnsubstancesghninghnan
dghnoutghnofghncellsghnandghnbetweenghncellghnorganellesghnandghncytosol
2.ghndetectghnchemicalghnmessengersghnarrivingghnatghntheghncellghnsurface
3.ghnlinkghnadjacentghncellsghntogetherghnbyghnmembraneghnjunctions
4.ghnanchorghncellsghntoghntheghnextracellularghnmatrix
integralghnmembraneghnproteinghn-
ghnCORRECTghnANSWER✔closelyghnassociated ghnwithghnmembraneghnlipids
can'tghnbeghnextractedghnfromghntheghnmembraneghnwithoutghndisruptingghntheghnlip
idghnbilayer
amphipathicghn(polarghnout,ghnnonpolarghnin)
someghncanghnmoveghnlaterallyghnbutghnothersghncan'tghnbecauseghntheyghnareghnlinke
dghntoghnperipheralghnproteins
,transmembraneghnproteinsghn-
ghnCORRECTghnANSWER✔Integralghnproteinsghnthatghnspanghntheghnmembra
ne.
peripheralghnmembraneghnproteinsghn-
ghnCORRECTghnANSWER✔locatedghnonghnmembraneghnsurfaceghnandghnareghn
boundghntoghntheghnpolarghnregionsghnofghnintegralghnproteins
notghnamphipathic
glycoalyxghn-
ghnCORRECTghnANSWER✔layerghnofghnstickyghncarbohydratesghncoveringghn
plasmaghnmembrane,ghnprovidesghnstrength,ghnattachmentghnandghncellghncellghnre
cognition,ghnanchoredghntoghntheghnplasmaghnmembraneghnbyghncarbohydratesghnb
ondedghntoghnproteinsghnandghnlipidsghninghntheghnmembrane
fluidghnmosaicghnmodelghn-
ghnCORRECTghnANSWER✔modelghnthatghndescribesghntheghnarrangementghna
ndghnmovementghnofghntheghnmoleculesghnthatghnmakeghnupghnaghncellghnmembrane
lipidghnraftsghn-ghnCORRECTghnANSWER✔cholesterol-
richghnregionsghnofghnreducedghnmembraneghnfluidityghnthatghnareghnbelievedghntoghn
serveghnasghnorganizingghncentersghnforghntheghngenerationghnofghncomplexghnintrac
ellularghnsignals
,integrinsghn-
ghnCORRECTghnANSWER✔Aghntransmembrane ghnproteinghnthatghninterconn
ectsghntheghnextracellularghnmatrixghnandghntheghncytoskeleton.
Desmosomesghn-
ghnCORRECTghnANSWER✔Anchoringghnjunctionsghnthatghnpreventghncellsghn
fromghnbeingghnpulledghnapart
Cadherinsghn-
ghnCORRECTghnANSWER✔proteinsghnthatghnextendghnfromghntheghncellghnintog
hntheghnextracellular ghnspace,ghnwhereghntheyghnlinkghnupghnandghnbindghnwithghncad
herinsghnfromghnanghnadjacentghncell
tightghnjunctionghn-
ghnCORRECTghnANSWER✔junction ghnthatghnformsghnbetweenghntwoghnadjace
ntghnplasmaghnmembranesghntoghnremoveghnextracellularghnspaceghnbetweenghnthe
m
occursghninghnaghnbandghnaroundghntheghnentireghncircumferenceghnofghntheghncell
gapghnjunctionsghn-
ghnCORRECTghnANSWER✔proteinghnchannelsghnthatghnlinkghntheghncytosolsghn
ofghnadjacentghncells
ghn
limitsghnwhatghncanghnpassghnbetweenghntheghncytosolsghnofghntheghnconnectedghncel
lsghntoghnsmallghnmoleculesghnandghnions
, simpleghndiffusionghn-
ghnCORRECTghnANSWER✔movementghnofghnaghnsoluteghnfromghnanghnareaghno
fghnhighghnconcentrationghntoghnanghnareaghnofghnlowghnconcentration
fluxghn-
ghnCORRECTghnANSWER✔theghnamountghnofghnmaterialghncrossingghnaghnsurf
aceghninghnaghnunitghnofghntime
netghnfluxghn-ghnCORRECTghnANSWER✔differenceghnbetweenghntwoghnone-
wayghnfluxes
determinesghnnetghngainghnforghncompartmentghn2ghnandghnnetghnlossghnforghncompar
tmentghn1
alwaysghngreaterghnfromghnregionsghnofghnhigherghnconc.ghntoghnlowerghnconc.
diffusionghnequilibriumghn-
ghnCORRECTghnANSWER✔stateghnduringghnwhichghndiffusionghnfluxesghninghn
oppositeghndirectionsghnareghnequal;ghnthatghnis,ghntheghnnetghnfluxghnequalsghnzero
factorsghnthatghnaffectghnnetghnfluxghn-
ghnCORRECTghnANSWER✔1.ghntemperature:ghnhigherghntempghn=ghnfasterghnn
etghnflux
2.ghnmassghnofghnmolecule:ghnlargerghnmoleculeghn=ghnslowerghnnetghnflux
3.ghnsurfaceghnarea:ghngreaterghnsurfaceghnareaghn=ghnfasterghnnetghnflux
4.ghnmedium:ghnairghn=ghnfasterghnnetghnflux
universalghnfunctionghnofghnmembranesghn-
ghnCORRECTghnANSWER✔toghnactghnasghnaghnselectiveghnbarrierghntoghntheghnpa
ssageghnofghnmolecules
functionsghnofghnplasmaghnmembranesghn-
ghnCORRECTghnANSWER✔1.ghnregulateghnpassageghnofghnsubstancesghninghnan
dghnoutghnofghncellsghnandghnbetweenghncellghnorganellesghnandghncytosol
2.ghndetectghnchemicalghnmessengersghnarrivingghnatghntheghncellghnsurface
3.ghnlinkghnadjacentghncellsghntogetherghnbyghnmembraneghnjunctions
4.ghnanchorghncellsghntoghntheghnextracellularghnmatrix
integralghnmembraneghnproteinghn-
ghnCORRECTghnANSWER✔closelyghnassociated ghnwithghnmembraneghnlipids
can'tghnbeghnextractedghnfromghntheghnmembraneghnwithoutghndisruptingghntheghnlip
idghnbilayer
amphipathicghn(polarghnout,ghnnonpolarghnin)
someghncanghnmoveghnlaterallyghnbutghnothersghncan'tghnbecauseghntheyghnareghnlinke
dghntoghnperipheralghnproteins
,transmembraneghnproteinsghn-
ghnCORRECTghnANSWER✔Integralghnproteinsghnthatghnspanghntheghnmembra
ne.
peripheralghnmembraneghnproteinsghn-
ghnCORRECTghnANSWER✔locatedghnonghnmembraneghnsurfaceghnandghnareghn
boundghntoghntheghnpolarghnregionsghnofghnintegralghnproteins
notghnamphipathic
glycoalyxghn-
ghnCORRECTghnANSWER✔layerghnofghnstickyghncarbohydratesghncoveringghn
plasmaghnmembrane,ghnprovidesghnstrength,ghnattachmentghnandghncellghncellghnre
cognition,ghnanchoredghntoghntheghnplasmaghnmembraneghnbyghncarbohydratesghnb
ondedghntoghnproteinsghnandghnlipidsghninghntheghnmembrane
fluidghnmosaicghnmodelghn-
ghnCORRECTghnANSWER✔modelghnthatghndescribesghntheghnarrangementghna
ndghnmovementghnofghntheghnmoleculesghnthatghnmakeghnupghnaghncellghnmembrane
lipidghnraftsghn-ghnCORRECTghnANSWER✔cholesterol-
richghnregionsghnofghnreducedghnmembraneghnfluidityghnthatghnareghnbelievedghntoghn
serveghnasghnorganizingghncentersghnforghntheghngenerationghnofghncomplexghnintrac
ellularghnsignals
,integrinsghn-
ghnCORRECTghnANSWER✔Aghntransmembrane ghnproteinghnthatghninterconn
ectsghntheghnextracellularghnmatrixghnandghntheghncytoskeleton.
Desmosomesghn-
ghnCORRECTghnANSWER✔Anchoringghnjunctionsghnthatghnpreventghncellsghn
fromghnbeingghnpulledghnapart
Cadherinsghn-
ghnCORRECTghnANSWER✔proteinsghnthatghnextendghnfromghntheghncellghnintog
hntheghnextracellular ghnspace,ghnwhereghntheyghnlinkghnupghnandghnbindghnwithghncad
herinsghnfromghnanghnadjacentghncell
tightghnjunctionghn-
ghnCORRECTghnANSWER✔junction ghnthatghnformsghnbetweenghntwoghnadjace
ntghnplasmaghnmembranesghntoghnremoveghnextracellularghnspaceghnbetweenghnthe
m
occursghninghnaghnbandghnaroundghntheghnentireghncircumferenceghnofghntheghncell
gapghnjunctionsghn-
ghnCORRECTghnANSWER✔proteinghnchannelsghnthatghnlinkghntheghncytosolsghn
ofghnadjacentghncells
ghn
limitsghnwhatghncanghnpassghnbetweenghntheghncytosolsghnofghntheghnconnectedghncel
lsghntoghnsmallghnmoleculesghnandghnions
, simpleghndiffusionghn-
ghnCORRECTghnANSWER✔movementghnofghnaghnsoluteghnfromghnanghnareaghno
fghnhighghnconcentrationghntoghnanghnareaghnofghnlowghnconcentration
fluxghn-
ghnCORRECTghnANSWER✔theghnamountghnofghnmaterialghncrossingghnaghnsurf
aceghninghnaghnunitghnofghntime
netghnfluxghn-ghnCORRECTghnANSWER✔differenceghnbetweenghntwoghnone-
wayghnfluxes
determinesghnnetghngainghnforghncompartmentghn2ghnandghnnetghnlossghnforghncompar
tmentghn1
alwaysghngreaterghnfromghnregionsghnofghnhigherghnconc.ghntoghnlowerghnconc.
diffusionghnequilibriumghn-
ghnCORRECTghnANSWER✔stateghnduringghnwhichghndiffusionghnfluxesghninghn
oppositeghndirectionsghnareghnequal;ghnthatghnis,ghntheghnnetghnfluxghnequalsghnzero
factorsghnthatghnaffectghnnetghnfluxghn-
ghnCORRECTghnANSWER✔1.ghntemperature:ghnhigherghntempghn=ghnfasterghnn
etghnflux
2.ghnmassghnofghnmolecule:ghnlargerghnmoleculeghn=ghnslowerghnnetghnflux
3.ghnsurfaceghnarea:ghngreaterghnsurfaceghnareaghn=ghnfasterghnnetghnflux
4.ghnmedium:ghnairghn=ghnfasterghnnetghnflux
