Chapter 1: Cellular Biology
l l l
MULTIPLElCHOICE
1. Whichlstatementlbestldescribeslthelcellularlfunctionloflmetaboliclabsorption?
a. Cellslcanlproducelproteins. c. Cellslcanltakelinlandluselnutrients.
b. Cellslcanlsecreteldigestivelenzymes. d.l Cellslcanlsynthesizelfats.
ANS:l C
Inlmetaboliclabsorption,lalllcellsltakelinlandluselnutrientslandlotherlsubstanceslfromltheirlsurro
undings.lThelremainingloptionslarelnotlinclusivelinltheirldescriptionsloflcellularlmetaboliclab
sorption.
PTS:l l 1 REF:l Pagel2
2. Mostloflalcell’slgeneticlinformation,lincludinglRNAlandlDNA,lislcontainedlinlthe:
a. Mitochondria c. Nucleolus
b. Ribosome d.l l Lysosome
ANS:l C
Thelnucleuslcontainslthelnucleolus,lalsmallldenselstructurelcomposedllargelyloflRNA,lmostlo
flthelcellularlDNA,landlthelDNA-
bindinglproteins,lsuchlaslthelhistones,lwhichlregulatelitslactivity.lThelotherloptionsldolnotlcon
tainlmostloflalcell’slgeneticlinformation.
PTS:l l 1 REF:l Pagel2
3. Whichl componentloflthelcelllprodNuUceRsSIhNyGd TroBg.CenO M
peroxide l(H2O2)l bylusingl oxygenl tolre
movelhydrogenlatomslfromlspecificlsubstrateslinlanloxidativelreaction?
a. Lysosomes c. Ribosomes
b. Peroxisomes d.l Oxyhydrosomes
ANS:l B
Peroxisomeslarelsolnamedlbecauseltheylusuallylcontainlenzymeslthatluseloxygenltolremovelhyd
rogenlatomslfromlspecificlsubstrateslinlanloxidativelreactionlthatlproduceslH2O2,lwhichlislalpow
erfulloxidantlandlpotentiallyldestructiveliflitlaccumulateslorlescapeslfromlperoxisomes.lRiboso
meslarelRNA-
proteinlcomplexesl(nucleoproteins)lthatlarelsynthesizedlinlthelnucleoluslandlsecretedlintolthelcy
toplasmlthroughlporeslinlthelnuclearlenvelopelcalledlnuclearlporelcomplexes.lLysosomeslarelsa
clikelstructureslthatloriginatelfromlthelGolgilcomplexlandlcontainlmorelthanl40ldigestivelenzym
eslcalledlhydrolases,lwhichlcatalyzelbondslinlproteins,llipids,lnucleiclacids,landlcarbohydrates.l
Oxyhydrosomesarelinvolvedlinlenzymelproduction.
PTS:l l 1 REF:l Pagel8
4. Whichlcelllcomponentlislcapableloflcellularlautodigestionlwhenlitlislreleasedlduringlcelllinju
ry?
a. Ribosome c. Smoothlendoplasmiclreticulum
b. Golgilcomplex d.l Lysosomes
ANS:l D
, Thellysosomallmembranelactslaslalprotectivelshieldlbetweenlthelpowerfulldigestivelenzymesl
withinlthellysosomelandlthelcytoplasm,lpreventingltheirlleakagelintolthelcytoplasmiclmatrix.l
Disruptionloflthelmembranelbylvariousltreatmentslorlcellularlinjurylleadsltolalreleaseloflthelly
sosomallenzymes,lwhichlcanlthenlreactlwithltheirlspecificlsubstrates,lcausinglcellularlself-
digestion.lThelotherloptionsldolnotlcorrectlyldescribelthislprocess.
PTS:l l 1 REF:l Pagesl7-8
5. Whatlislthelsequenceloflstepslinltheldevelopmentloflaldigestivelenzymelbylthelpancreaslcellsl
fromlthelinitialltranscriptionltolthelreleaselfromlthelcell?
a. ThelenzymelisltranscribedlfromlDNAlbylRNAlinlthelnucleus,lproceedsltolthelribo
somelforlsynthesis,landlisltransportedlinlalsecretorylvesicleltolthelcelllmembrane.
b. ThelenzymelisltranscribedlfromlRNAlbylDNAlinlthelnucleus,lproceedsltolthellysosom
elforlsynthesis,landlisltransportedlinlanlencapsulatedlmembraneltolthelcelllmembrane.
c. Thelenzymelisltranscribedlbylthelmitochondrialinlthelnucleus,lproceedsltolthelriboso
melforlsynthesis,landlisltransportedlinlalcytoskeletonltolthelcelllmembrane.
d. ThelenzymelisltranscribedlfromlDNAlbylRNAlinlthelnucleus,lproceedsltolthelGolgilc
omplexlforlsynthesis,landlisltransportedlinlalcytosolltolthelcelllmembrane.
ANS:l A
ThelenzymelisltranscribedlfromlDNAlbylRNAlinlthelnucleus,lproceedsltolthelribosomelforlsyn
thesis,landlisltransportedlinlalsecretorylvesicleltolthelcelllmembrane.lThelotherloptionsldolnotl
correctlyldescribelthislprocess.
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PTS:l l 1 REF:l Pagel7l|lFigurel1-5
6. DuringlwhichlphaseloflthelcelllcyclelislDNAlsynthesized?
a. G1 c. G2
b. S d.l M
ANS:l B
Thelfourldesignatedlphasesloflthelcelllcyclelare:l(1)lthelG1lphasel(Gl=lgap),lwhichlislthelperiodlb
etweenlthelMlphasel(Ml=lmitosis)landlthelstartloflDNAlsynthesis;l(2)lthelSlphasel(Sl=lsynthesis)
,lduringlwhichlDNAlislsynthesizedlinlthelcelllnucleus;l(3)lthelG2lphase,lduringlwhichlRNAlandl
proteinlsynthesisloccurs,lthelperiodlbetweenlthelcompletionloflDNAlsynthesislandlthelnextlpha
sel(M);landl(4)lthelMlphase,lwhichlincludeslnuclearlandlcytoplasmicldivision.
PTS:l l 1 REF:l Pagel37
7. Whatlorganiclcompoundlfacilitatesltransportationlacrosslcelllmembraneslbylactinglaslrec
eptors,ltransportlchannelslforlelectrolytes,landlenzymesltoldrivelactivelpumps?
a. Lipids c. Proteins
b. Proteases d.l Carbohydrates
ANS:l C
, Proteinslactlasl(1)lrecognitionlandlbindinglunitsl(receptors)lforlsubstanceslmovinglinlandloutlo
flthelcell;l(2)lporeslorltransportlchannelslforlvariouslelectricallylchargedlparticleslcalledlionslo
rlelectrolyteslandlspecificlcarrierslforlaminolacidslandlmonosaccharides;land
(3)lspecificlenzymeslthatldrivelactivelpumpslthatlpromotelthelconcentrationloflcertainlions,lpa
rticularlylpotassiuml(K+),lwithinlthelcelllwhilelkeepinglconcentrationsloflotherlions,lforlexam
ple,lsodiuml(Na+),lbelowlthelconcentrationslfoundlinlthelextracellularlenvironment.lThelothe
rloptionsldolnotlcorrectlyldescribelthislprocess.
PTS:l l 1 REF:l Pagel13l|lPagel15
8. Understandinglthelvariouslstepsloflproteolyticlcascades,lsuchlaslcaspase-
mediatedlapoptosislandlcomplementlcascades,lmaylbelusefullinldesigningldrugltherapylforl
whichlhumanldiseases?
a. Cardiaclandlvascularldisorders
b. Autoimmunelandlmalignantldisorders
c. Gastrointestinallandlrenalldisorders
d. Endocrinelandlgastrointestinalldisorders
ANS:l B
Understandinglthelvariouslstepslinvolvedlinlthislprocesslislcruciallforldesigningldruglinterven
tions.lDysregulationloflproteaseslfeatureslprominentlylinlmanylhumanldiseases,lincludinglcan
cer,lautoimmunity,landlneurodegenerativeldisorders.lThelotherloptionsldolnotlcorrectlyldescr
ibelthislprocess.
PTS:l l 1 REF:l l Pagel15
9. Whichlstructurelpreventslwater-
solublelmoleculeslfromlenteringlcellslacrosslthelplasmal NURSINGTB.COM
membrane?
a. Carbohydratelchains c. Membranelchannellproteins
b. Glycoproteinlchannels d.l Lipidlbilayer
ANS:l D
Thelbilayer’slstructurelaccountslforloneloflthelessentiallfunctionsloflthelplasmalmembrane.lItli
slimpermeableltolmostlwater-
solublelmoleculesl(moleculeslthatldissolvelinlwater)lbecauselthelwater-
solublelmoleculeslarelinsolublelinltheloilylcorelregion.lThelbilayerlserveslaslalbarrierltoltheldif
fusionloflwaterlandlhydrophiliclsubstanceslwhilelallowingllipid-
solublelmolecules,lsuchlasloxygenl(O2)landlcarbonldioxidel(CO2),ltoldiffuselthroughlitlreadil
y.lThelotherloptionsldolnotlcorrectlyldescribelthislprocess.
PTS:l l 1 REF:l Pagesl12-13
10. Thelfluidlmosaiclmodellexplains:
a. Howlalcelllmembranelfunctions
b. Whylourlbodieslappearltolbelsolid
c. Howltissuelisldifferentiated
d. Howlfluidlmoveslbetweenlthelintracellularlandlextracellularlcompartments
ANS:l A
Thelfluidlmosaiclmodellaccountslforlthelflexibilityloflcellularlmembranes,ltheir
self-
sealinglproperties,landltheirlimpermeabilityltolmanylsubstances.lThelremainingloptionsldolno
tlexplainlthelmosaiclmodel.
, PTS:l l 1 REF:l Pagel12l|lWhat'slNewlbox
11. Whichlformloflcelllcommunicationlislusedltolcommunicatelwithinlthelcelllitselflandlwithlothe
rlcellslinldirectlphysicallcontact?
a. Proteinlchannell(gapljunction)
b. Plasmalmembrane–boundlsignalinglmoleculesl(involvinglreceptors)
c. Hormonelsecretionlsuchlaslneurotransmitters
d. Extracellularlchemicallmessengerslsuchlaslligands
ANS:l A
Cellslcommunicatelbylusinglhundredsloflkindsloflsignallmolecules,lforlexample,linsulin.lCells
lcommunicatelinlthreelmainlways;ltheyldisplaylplasmalmembrane–
boundlsignalinglmoleculesl(receptors)lthatlaffectlthelcelllitselflandlotherlcellslinldirectlphysic
allcontact.lThelotherloptionsldolnotlcorrectlyldescribelthislprocess.
PTS:l l 1 REF:l Pagel20
12. Whichlmodeloflchemicallsignalingluseslbloodltoltransportlcommunicationltolcellslsomeldist
ancelaway?
a. Paracrine c. Neurotransmitter
b. Autocrine d.l Hormonal
ANS:l D
Chemicallsignalinglcanlbelclassifiedlintolthreelcategories:l(1)llocal-
chemicallmediator,l(2)lhormone,landl(3)lneurotransmitter.lInlthellocal-
chemicallmediatorlmodel,lthelsecretedlchemicallactslonlthelcellslinlthelimmediatelenvironmen
t.lHormoneslarelusedlforlcommunicationl withl distantltarge tNcUeRl lSsI. NFGoTr Be.xCaOmMp le , l cellsl canl se
cretelalchemicallandl relylonlthelbloodlsystemltoldeliverlthelsignalltolaldistantlcell.lFinally,lneurotra
nsmitterslarelsecretedlbylneuronsltolstimulatelanladjoininglcell.lForlexample,lalneuronlmightlse
cretelacetylcholineltolstimulatelthelmovementloflalmusclelcell.
PTS:l l 1 REF:l Pagel20
13. Whichlmodeloflchemicallsignalinglusesllocallchemicallmediatorslthatlarelquicklyltakenlup,l
destroyed,lorlimmobilized?
a. Paracrine c. Neurotransmitter
b. Autocrine d.l Hormone
ANS:l A
Inlparacrinelsignaling,lcellslsecretellocallchemicallmediatorslthatlarelquicklyltakenlup,ldestroy
ed,lorlimmobilized.lThelotherloptionsldolnotlcorrectlyldescribelthislprocess.
PTS:l l 1 REF:l Pagel20
14. Neurotransmitterslaffectlthelpostsynapticlmembranelbylbindinglto:
a. Lipidsl c. Amphipathicllipids
b. Ribosomes d.l Receptors
ANS:l D
Inleachltypeloflchemicallsignaling,ltheltargetlcelllreceiveslthelsignallbylfirstlattachingltolitslrece
ptors.lThelotherloptionsldolnotlcorrectlyldescribelthislprocess.