BIOLOGY 190 FINAL EXAM STUDY
GUIDE QUESTIONS AND CORRECT
ANSWERS
Nucleotideastructurea-aans--monomersaofanucleicaacids
everyanucleotideaconsistsaofa3aparts:a5acarbonasugar,anegativelyachargedaphosphateagro
up,anitrogenousabase
Nucleicaacida-aans--includesaDNAaandaRNA
polymeraconsistingaofamanyanucleotideamonomers
twoastrandsaheldatogetherabyahydrogenabonds
DNAa-aans--
doubleastrandedahelicalanucleicaacidamoleculeaconsistingaofanucleotideamonomersawithad
eoxyriboseasugaraandanitrogenousabasesaA,aT,aC,aGa
providesadirectionsaforaitsaownareplication
sugaraphosphateabackbone
5'aendaisaphosphateaonacarbona5aanda3'aisaattachedatoaOHagroupaonacarbona3
RNAa-aans--usedaforaproteinasynthesis
UainsteadaofaT
Riboseasugar
muchadifferentaplaceathanaDNA
singlestranded
riboseahasaanaextraaoxygenaandaisaveryareactiveaandalessastableathanaDNA
DNAareplicationa-aans--
1aparentalamoleculeayieldsa2aidenticaladaughteraDNAamoleculesa(semiconservative)
strandsaassembledafromafreefloatinganucleotidesaandaaddedausingaenzymes
DNAahelicaseauntwistsaDNAaandamakesabubbles
DNAapolymeraseacatalyzesanucleotideaformationaofadaughterastrandaandaproofreads
DNAaligaseaconnectsagrowingastrand
leadingastrandaisacontinuousaandalaggingaisanotabecauseaDNAaisaantiparallel
CentralaDogmaa-aans--
DNAaisatranscribedaintoaRNAamovesatoanucleusaRNAaisatranslatedaintoaproteins
Transcriptiona-aans--synthesisaonaRNAaunderatheadirectionaofaDNA
DNAatoamRNA
inanucleus
DNAagetsauntwistedaandaseparatedabutaonlyaoneastrandaisatranscribeda(templateastrand)
hydrogenabondsaformabetweenatemplateastrandaandamRNA
, Initiation-abindsatoapromoterasequenceaofaRNAaandabeginsasynthesis
Elongation-aRNAastrandapeelsaawayaandanucleotidesaareaaddedatoaRNA
Termination-aeverythingaseparatesa(DNA,RNA,aRNAapolymerase)
promoteraDNA'amatureawhenahasasmallaGacapaandapolyAatailaandaintronsaoutaandaexonsas
plicedatogether
Translationa-aans--theasynthesisaofaproteinaunderatheadirectionaofaRNA
mRNAatoaprotein
ribosomesaareawhereaitatakesaplace
codonsa(startaAUGaandastopaUGA)aandaeachaspecifiesaforaaaprotein
tRNA-atRNAaisainterpreterathatahelpsaanticodonsamatchawithacodons
ribosomeahaveabothasmallaandalargeasubunitsaandatheyabringamRNAaandatRNAacloseasoat
heyacanabond.
Initiation-astartacodonaattachesatoasmallaunitaandathealargeasubunitaadds
Elongation-
acodonarecognitionabetweenacodonaandaanticodon,apeptideabondaformation,atranslocation
aPasiteatRNAaleavesaribosomeaandaribosomeatranslocatesatRNAainaAasiteatoaPasite
termination-astopacodons-areleaseafactorabindsatoastopacodonasignalingatheaend
mRNAaprocessinga-aans--PolyaAatail,asmallaGacap,aintronsaout,aexonsasplicing
Mutationsa-aans--permanentachangeainabaseasequenceaofaDNAawithinaaagene.
Nucleotideabaseasubstitutionsaonlyaonealetterachange
Silentamutation:aNoaconsequences
MissenseaMutation:aaffectsaaminoaacid
Nonsense:aaffectsaaminoaacidabyamakingaitaaastopacodona(alwaysabad)
Frameshiftamutation-ainsertionaoradeletion-
ashiftsareadingaframe.aCanabeasilent,amissense,aoranonsense
Lacaoperona-aans--
Promoter,aoperator,a3alactoseagenes,arepressor.aWhenalactoseaisaabsent-
arepressorabindsatoaoperatoraandalactoseadoesanotagetamade.
Whenalactoseaisathere-ainactivearepressoraandaRNAapolymeraseabindsatoapromoteraand
makesaenzymesathatahelp
Moleculea-aans--heldatogetherabyacovalentabondsa
covalentabonds-atheastrongestabond,a2aatomsashareaoneaoramoreapairsaofaelectrons
Non-polara-aans--Atomsaexertaanaequalapullaonatheaelectrons
theaelectronsaareasharedaequallya
(hydrophobic)
Polara-aans--unequalasharingaofaelectrons
negativelyachargesaelectronsagetapulledacloseratoatheamoreaelectronegativeaatomaandaitam
akesatheaatomapartiallyanegativeaandatheaotheraatomapartiallyapositivea
(prettyamuchaanythingawithaoxygen)a
GUIDE QUESTIONS AND CORRECT
ANSWERS
Nucleotideastructurea-aans--monomersaofanucleicaacids
everyanucleotideaconsistsaofa3aparts:a5acarbonasugar,anegativelyachargedaphosphateagro
up,anitrogenousabase
Nucleicaacida-aans--includesaDNAaandaRNA
polymeraconsistingaofamanyanucleotideamonomers
twoastrandsaheldatogetherabyahydrogenabonds
DNAa-aans--
doubleastrandedahelicalanucleicaacidamoleculeaconsistingaofanucleotideamonomersawithad
eoxyriboseasugaraandanitrogenousabasesaA,aT,aC,aGa
providesadirectionsaforaitsaownareplication
sugaraphosphateabackbone
5'aendaisaphosphateaonacarbona5aanda3'aisaattachedatoaOHagroupaonacarbona3
RNAa-aans--usedaforaproteinasynthesis
UainsteadaofaT
Riboseasugar
muchadifferentaplaceathanaDNA
singlestranded
riboseahasaanaextraaoxygenaandaisaveryareactiveaandalessastableathanaDNA
DNAareplicationa-aans--
1aparentalamoleculeayieldsa2aidenticaladaughteraDNAamoleculesa(semiconservative)
strandsaassembledafromafreefloatinganucleotidesaandaaddedausingaenzymes
DNAahelicaseauntwistsaDNAaandamakesabubbles
DNAapolymeraseacatalyzesanucleotideaformationaofadaughterastrandaandaproofreads
DNAaligaseaconnectsagrowingastrand
leadingastrandaisacontinuousaandalaggingaisanotabecauseaDNAaisaantiparallel
CentralaDogmaa-aans--
DNAaisatranscribedaintoaRNAamovesatoanucleusaRNAaisatranslatedaintoaproteins
Transcriptiona-aans--synthesisaonaRNAaunderatheadirectionaofaDNA
DNAatoamRNA
inanucleus
DNAagetsauntwistedaandaseparatedabutaonlyaoneastrandaisatranscribeda(templateastrand)
hydrogenabondsaformabetweenatemplateastrandaandamRNA
, Initiation-abindsatoapromoterasequenceaofaRNAaandabeginsasynthesis
Elongation-aRNAastrandapeelsaawayaandanucleotidesaareaaddedatoaRNA
Termination-aeverythingaseparatesa(DNA,RNA,aRNAapolymerase)
promoteraDNA'amatureawhenahasasmallaGacapaandapolyAatailaandaintronsaoutaandaexonsas
plicedatogether
Translationa-aans--theasynthesisaofaproteinaunderatheadirectionaofaRNA
mRNAatoaprotein
ribosomesaareawhereaitatakesaplace
codonsa(startaAUGaandastopaUGA)aandaeachaspecifiesaforaaaprotein
tRNA-atRNAaisainterpreterathatahelpsaanticodonsamatchawithacodons
ribosomeahaveabothasmallaandalargeasubunitsaandatheyabringamRNAaandatRNAacloseasoat
heyacanabond.
Initiation-astartacodonaattachesatoasmallaunitaandathealargeasubunitaadds
Elongation-
acodonarecognitionabetweenacodonaandaanticodon,apeptideabondaformation,atranslocation
aPasiteatRNAaleavesaribosomeaandaribosomeatranslocatesatRNAainaAasiteatoaPasite
termination-astopacodons-areleaseafactorabindsatoastopacodonasignalingatheaend
mRNAaprocessinga-aans--PolyaAatail,asmallaGacap,aintronsaout,aexonsasplicing
Mutationsa-aans--permanentachangeainabaseasequenceaofaDNAawithinaaagene.
Nucleotideabaseasubstitutionsaonlyaonealetterachange
Silentamutation:aNoaconsequences
MissenseaMutation:aaffectsaaminoaacid
Nonsense:aaffectsaaminoaacidabyamakingaitaaastopacodona(alwaysabad)
Frameshiftamutation-ainsertionaoradeletion-
ashiftsareadingaframe.aCanabeasilent,amissense,aoranonsense
Lacaoperona-aans--
Promoter,aoperator,a3alactoseagenes,arepressor.aWhenalactoseaisaabsent-
arepressorabindsatoaoperatoraandalactoseadoesanotagetamade.
Whenalactoseaisathere-ainactivearepressoraandaRNAapolymeraseabindsatoapromoteraand
makesaenzymesathatahelp
Moleculea-aans--heldatogetherabyacovalentabondsa
covalentabonds-atheastrongestabond,a2aatomsashareaoneaoramoreapairsaofaelectrons
Non-polara-aans--Atomsaexertaanaequalapullaonatheaelectrons
theaelectronsaareasharedaequallya
(hydrophobic)
Polara-aans--unequalasharingaofaelectrons
negativelyachargesaelectronsagetapulledacloseratoatheamoreaelectronegativeaatomaandaitam
akesatheaatomapartiallyanegativeaandatheaotheraatomapartiallyapositivea
(prettyamuchaanythingawithaoxygen)a
