AQA A LEVEL BIOLOGY - PAPER 3
(SYNOPTIC) QUESTIONS AND
ANSWERS
Whatxcarexcthexcusefulxcpropertiesxcofxcwaterxcandxcwhyxc?xc-xcanswer--
1)xcWaterxcisxcaxcmetabolitexc-
xcinxcmanyxcmetabolicxcreactionsxcincludingxccondensationxcandxchydrolysisxc
2)xcWaterxcisxcaxcsolventxc-
xcmediumxcinxcwhichxcenzymexccatalysedxcreactionsxctakexcplacexc(metabolicxcreactionsxc)
xcandxcreadilyxcdissolvesxcsubstancesxclikexcinorganicxcionsxc(xcasxcwaterxcisxcdipolarxcsoxct
otallyxcsurroundsxcthexcions)xc,xcexcretoryxcproductsxc(urea/
ammonia)xc,xcrespiratoryxcgasesxcandxcsmallxchydrophilicxcmoleculesxc(xcaminoxcacidsxc,xc
etc)
3)xcWaterxchasxcaxchighxclatentxcheatxcofxcvaporisationxc(lotsxcofxcenergyxcrequiredxctoxcbrea
kxchydrogenxcbondsxcbetweenxcwaterxcmoleculesxcsoxcaxclotxcofxcenergyxcisxcusedxcupxcwhe
nxcwaterxcevaporatesxc)xcsoxchelpsxcwithxctemperaturexccontrolxcasxcevaporationxcofxcswea
txccoolsxchumansxcdownxc
4)xcWaterxchasxcaxchighxcspecificxcheatxccapacityxc(xctoxcseparatexcthexcmanyxchydrogenxcb
ondsxcrequiresxcaxclotxcofxcenergy)xcsoxcactsxcasxcaxcbufferxcandxcresistsxctemperaturexccha
ngesxctoxcmaintainxcaxcconstantxcinternalxcbodyxctemperaturexc
5)xcWaterxchasxclargexccohesivexcforcesxc(xcasxchydrogenxcbondsxcstickxctogether)xcsoxcallo
wsxctransportationxcofxcsubstances(xcwaterxctravellingxcinxccolumnsxcinxcxylem)xcandxcmea
nsxcwaterxchasxcaxchighxcsurfacexctensionxcwhenxcitxccomesxcintoxccontactxcwithxcairxc(xcallo
wingxcpondxcskatersxctoxcwalkxconxcitsxcsurface)
Whyxcisxcwaterxcdipolarxc?xc-xcanswer--
Asxcwaterxcisxcmadexcupxcofxctwoxchydrogenxcatomsxcandxconexcoxygenxcatomxc,xcthexchydr
ogenxcatomsxchavexcaxcslightlyxcpositivexcpolexcandxcthexcoxygenxcatomxchasxcaxcslightlyxcn
egativexcpolexcmakingxcwaterxcdipolar.
Hydrogenxcbondsxc-xcanswer--
Slightlyxcnegativelyxcchargedxcoxygenxcatomxcisxcattractedxctoxcthexcslightlyxcpositivelyxcch
argedxchydrogenxcatomxcofxcotherxcwaterxcmolecules.xcThexcattractionxcbetweenxcopposit
excchargesxcisxccalledxchydrogenxcbonding,xcwhichxcarexcweakxcbondsxcbutxcstrongxcinxclar
gexcnumbers.xcThisxcmakesxcwaterxcaxcmajorxccomponentxcinxccells
Hydrolysisxc-xcanswer--
Breaksxcaxcbondxcbetweenxctwoxcmoleculesxcbyxcthexcadditionxcofxcaxcmoleculexcofxcwater
Condensationxc-xcanswer--
Joinsxctwoxcmoleculesxctogetherxcwithxcthexcformationxcofxcaxcbondxcbyxcthexcremovalxcofxca
xcmoleculexcofxcwater
,Polymerxc-xcanswer--
Axcmoleculexc(xccarbohydrate,xcnucleotidexcorxcprotein)xcmadexcupxcofxcmanyxcmonomersxc
(xcsmallxcrepeatingxcunits)xcjoinedxctogetherxcbyxccondensationxcreactionsxcandxcbrokenxcd
ownxcmyxchydrolysis
Monosaccharidesxc-xcanswer--
Arexcthexcmonomersxcfromxcwhichxclargerxccarbohydratesxcarexcmadexcandxccontainxcthexc
elementsxcCxcHxcandxcO.xcTheyxcarexcsweetxcandxcsolublexcandxctherexcarexcthreexctypesxc:x
cfructosexc,xcglucosexcandxcgalactose.xcHexosexcsugarsxc(glucose)xchavexcthexcformulaxcC
6H12O6
Glucosexcisxcthexcproductxcofxcphotosynthesisxcandxcaxcmajorxcsubstratexcofxcrespirationxc,x
cdrawxcthexctwoxcstructuralxcisomersxcofxcglucosexcinxclongxcandxcshortxchandxcandxcstatexct
hexcdifferencexcbetweenxcthemxc-xcanswer--
Onxccarbonxc1xcinxcbetaxcglucosexcthexchydroxylxcgroupxc(OH)xcpointsxcupwardsxcandxcinxca
lphaxcglucosexcthexchydroxylxcgroupxcpointsxcdownxconxccarbonxc1
Sucrosexc-xcanswer--Glucosexcandxcfructose
Maltosexc-xcanswer--Glucosexcandxcglucose
Lactosexc-xcanswer--Glucosexcandxcgalactose
Howxcdoxcmonosaccharidesxcjoinxctogetherxc-xcanswer--
Byxccondensationxctoxcformxcaxcglycosidicxcbondxcbetweenxctwoxcmonosaccharidesxcandxc
axcdisaccharidexcandxcaxcmoleculexcofxcwaterxcarexcformed
Disaccharidexc-xcanswer--
Twoxcmonosaccharidesxcjoinedxctogetherxcbyxccondensationxcformingxcaxcglycosidicxcbon
d.xcTherexcarexcthreexctypesxc:xcmaltose,xcsucrosexcandxclactose.xcTheyxchavexcthexcchemi
calxcformulaxcC12H22O11
Drawxcthexchydrolysisxcofxcmaltosexcinxcstructuralxcformulaxcandxcshortxchandxcformulaxc-
xcanswer--
Testxcforxcstarchxc-xcanswer--
Addxciodinexcsolutionxctoxcthexctestxcsamplexc,xcifxcstarchxcisxcpresentxccolourxcchangesxcfro
mxcyellowxctoxcaxcblue-blackxccolour.
Testxcforxcaxcreducingxcsugarxc-xcanswer--
HeatxcwithxcBenedict'sxcreagentxc(xcblue)xcandxcifxcreducingxcsugarxcisxcpresentxcaxcbrickxcre
dxcprecipitatexcwillxcform
IssuesxcwithxcthexcBenedict'sxctestxc?xc-xcanswer--1)xcItxcisxcnonxcspecificxc-
xcdoesn'txctellxcwhichxcreducingxcsugarxcisxcpresentxc,xcaxcbiosensorxccanxcbexcusedxctoxcdet
ectxcforxcspecificxcsugarsxc
2)xcIt'sxcqualitativexcsoxccolourxcchangexcisxcbeingxcmeasuredxcsoxccan'txcobtainxcconcentra
tionxcofxcreducingxcsugarxcbutxcallowsxcanxcestimatexcforxchowxcmuchxcisxcpresentxcinxcthexcs
trengthxcofxcthexccolour
,3)xcIsxcsubjective
Howxctoxcquantifyxcresultsxconxcthexcconcentrationxcofxcunknownxcglucosexcconcentration
?xc-xcanswer--
Usexcaxccolorimeter,xcasxcaxcserialxcdilutionxcofxcknownxcglucosexcconcentrationsxccanxcbex
cmeasuredxcproducingxcaxcsetxcofxcsolutionsxcwithxcknownxcconcentrationsxc.xcThexcBenedi
ct'sxctestxccanxcbexcperformedxcwithxceachxcofxcthesexcandxcthexccolourxcintensityxcmeasure
d.xcAxcCALIBRATIONxcCURVExccanxcbexcproducedxcfromxcthexcresultsxcandxcusedxctoxcrea
dxciffxcthexcconcentrationxcofxcglucosexcinxcanxcunknownxcsolution.
Testxcforxcaxcnon-reducingxcsugarxc?xc-xcanswer--
HeatxcthexcsamplexcwithxcBenedict'sxcreagentxcandxcifxctherexcisxcnoxccolourxcchangexcaxcre
ducingxcsugarxcisxcnotxcpresentxcbutxcaxcnon-reducingxcsugarxccouldxcbe.
Heatxcaxcfreshxcsamplexcwithxcdilutexcacidxc(xcwhichxcwillxchydrolysexcthexcnonxcreducingxcs
ugarxcintoxcitsxcconstituentxcmonosaccharides).
NeutralisexcwithxcalkalixcandxccarryxcoutxcthexcBenedict'sxctestxcagainxc
Ifxcthexctestxcisxcpositivexcforxcaxcnon-
reducingxcsugarxcitxcwillxcformxcaxcbrickxcredxcprecipitate
Polysaccharidexc-xcanswer--Threexcmainxctypesxc-
xcstarchxc,xcglycogenxcandxccellulosexcwhichxcarexcchainsxcofxcmanyxcmonomersxcofxcgluco
sexcformedxcinxccondensationxcreactions.
Starchxc-xcanswer--
Starchxcisxcusedxcforxcenergyxcstoragexcinxcplantsxcandxcisxcmadexcfromxccondensationxcofxc
alphaxcglucose.
Amylose-xccompactxchelicalxcchainsxcsoxcstorexclotsxcofxcglucosexcinxcaxcsmallxcspacexc
Amylopectinxc-
xcbranchedxcchainsxcwhichxcallowxcmanyxcendsxctoxcbexcquicklyxchydrolysedxcbyxcamylasex
cenzymesxctoxcreleasexcglucosexc
Insolublexcandxclargexcsoxcnoxcosmoticxceffectsxc,xcinertxcandxccannotxcdiffusexcoutxcofxcthexc
cellsxcwhichxctheyxcarexcstoredxcinxc.
Cellulosexc-xcanswer--
Majorxccomponentxcofxcplantxccellxcwallsxcmadexcupxcofxcbetaxcglucosexcmonomerxcinxcaxcc
ondensationxcreaction.
Chainsxcofxcbetaxcglucosexcmoleculesxcformxclongxcstraightxcunbranchedxcchains.
Thesexcchainsxcrunxcparallelxctoxceachxcotherxcandxchydrogenxcbondsxcformxccross-
linkagesxcbetweenxcchains.xcThesexcmanyxchydrogenxcbondsxcprovidexchighxctensilexcstre
ngthxcwhichxcmakesxcthexccellxcwallxcrigidxcandxcpreventsxcosmoticxclysis
Hydrogenxcbondsxcalsoxcformxcstrongxcfibresxccalledxcmicrofibrilsxcwhichxcarexcgroupedxcin
toxcfibresxcwhichxcprovidexcstructuralxcsupport.
Glycogenxc-xcanswer--
Energyxcstoragexcmoleculexcinxcanimalsxcfoundxcinxcliverxccellsxcandxcinxcmusclexctissuexca
ndxcisxcmadexcfromxcthexccondensationxcofxcalphaxcglucose.xc
Compactxcsoxcstorexclotsxcofxcglucosexcinxcaxcsmallxcspacexc
Isxcquicklyxchydrolysedxctoxcreleasexcsolublexcglucosexcasxcmanyxcendsxcforxcamylasexcenz
ymesxctoxcattackxc
, Largexcandxcinsolublexcsoxcnoxcosmoticxceffectsxc,xcinertxcandxccannotxcdiffusexcoutxcofxcthex
ccellsxcwhichxctheyxcarexcstoredxcinxc.
Namexcthexc4xcinorganicxcionsxcandxcstatexctheirxcrolexc-xcanswer--
Inorganicxcionsxcoccurxcinxcsolutionxcinxcthexccytoplasmxcandxcbodyxcfluidsxc(xcbloodxc,xctissu
excfluid)xc
Hydrogenxcionsxc-
xcaffectsxcpHxclevels,xcthexchigherxcthexcconcentrationxcofxcH+xcionsxcthexclowerxcthexcpH(xc
morexcacidxc)xc
Ironxcionsxc-
xcimportantxccomponentxcofxchaemoglobinxcwhichxccarriesxcoxygenxcaroundxcthexcbodyxcin
xcthexcredxcbloodxccellsxc
Phosphatexcionsxc-
xccomponentxcofxcDNAxc,xcATPxc,xcRNAxcandxcphospholipidsxc,xcbondsxcbetweenxcphospha
texcgroupsxcstorexcenergyxcinxcATPxc
Sodiumxcionsxc-
xcinvolvedxcinxcthexcabsorptionxcofxcglucosexcandxcaminoxcacidsxcinxccoxctransportxcinxcthexcs
mallxcintestine
Aminoxcacidsxc-xcanswer--
Arexcthexcmonomersxcfromxcwhichxcpolypeptidesxcarexcmade.xcProteinsxcarexcmadexcupxco
fxconexcorxcmorexcpolypeptidexcchains.xcAllxcaminoxcacidsxccontainxcthexcelementsxcCxcHxcO
xcandxcNxcandxcarexcmadexcupxcofxcanxcaminoxcgroupxc(NH2)xc,xcaxccarboxylicxcacidxcgroupxc(
COOH)xcandxcaxcvariablexcgroupxc(R)
Whatxcisxcaxcconjugatedxcproteinxc?xc-xcanswer--Axcproteinxcwithxcaxcnon-
proteinxcchemicalxcgroupxcattached
Drawxcthexcstructurexcofxcanxcaminoxcacidxc-xcanswer--
Howxcmanyxcaminoxcacidsxcarexctherexcthatxcarexcsharedxcinxcallxcorganismsxc?xc-xcanswer--
20xcaminoxcacidsxcthatxcdifferxcbyxcaxcdifferentxcvariablexcgroup.
Dipeptidexc-xcanswer--
Twoxcaminoxcacidsxcjoinxctoxcformxcaxcdipeptidexcandxcaxcpeptidexcbongxcisxcformedxcbetwe
enxcthexcaminoxcacidsxcbyxcaxccondensationxcreaction.
Drawxcthexcformationxcofxcaxcdipeptidexcfromxctwoxcaminoxcacids?xc-xcanswer--
Describexcthexcproteinxcstructurexc?xc-xcanswer--Primaryxcstructurexc-
xcsequencexcofxcaminoxcacidsxcinxcaxcpolypeptidexcchainxc
Secondaryxcstructurexc-
xcfoldingxcofxcpolypeptidexcchainxccausingxchydrogenxcbondsxctoxcformxcbetweenxcaminoxca
cidsxccausingxcthexcformationxcofxcanxcalphaxchelixxcorxcaxcbetaxcpleatedxcsheetxc
Tertiaryxcstructurexc-
xcthexcfurtherxcfoldingxcofxcthexcsecondaryxcstructurexcwhichxcisxcheldxcintoxcshapexcbyxcbon
dsxce.g.xchydrogen,xcionicxcandxcdisulphide.xcBondsxcformxcbetweenxcRxcgroupsxcofxcamin
oxcacidsxcformingxcaxc3Dxcstructurexcandxcisxcthexcfinalxcstructurexcofxconexcpolypeptidexcch
ainxc
(SYNOPTIC) QUESTIONS AND
ANSWERS
Whatxcarexcthexcusefulxcpropertiesxcofxcwaterxcandxcwhyxc?xc-xcanswer--
1)xcWaterxcisxcaxcmetabolitexc-
xcinxcmanyxcmetabolicxcreactionsxcincludingxccondensationxcandxchydrolysisxc
2)xcWaterxcisxcaxcsolventxc-
xcmediumxcinxcwhichxcenzymexccatalysedxcreactionsxctakexcplacexc(metabolicxcreactionsxc)
xcandxcreadilyxcdissolvesxcsubstancesxclikexcinorganicxcionsxc(xcasxcwaterxcisxcdipolarxcsoxct
otallyxcsurroundsxcthexcions)xc,xcexcretoryxcproductsxc(urea/
ammonia)xc,xcrespiratoryxcgasesxcandxcsmallxchydrophilicxcmoleculesxc(xcaminoxcacidsxc,xc
etc)
3)xcWaterxchasxcaxchighxclatentxcheatxcofxcvaporisationxc(lotsxcofxcenergyxcrequiredxctoxcbrea
kxchydrogenxcbondsxcbetweenxcwaterxcmoleculesxcsoxcaxclotxcofxcenergyxcisxcusedxcupxcwhe
nxcwaterxcevaporatesxc)xcsoxchelpsxcwithxctemperaturexccontrolxcasxcevaporationxcofxcswea
txccoolsxchumansxcdownxc
4)xcWaterxchasxcaxchighxcspecificxcheatxccapacityxc(xctoxcseparatexcthexcmanyxchydrogenxcb
ondsxcrequiresxcaxclotxcofxcenergy)xcsoxcactsxcasxcaxcbufferxcandxcresistsxctemperaturexccha
ngesxctoxcmaintainxcaxcconstantxcinternalxcbodyxctemperaturexc
5)xcWaterxchasxclargexccohesivexcforcesxc(xcasxchydrogenxcbondsxcstickxctogether)xcsoxcallo
wsxctransportationxcofxcsubstances(xcwaterxctravellingxcinxccolumnsxcinxcxylem)xcandxcmea
nsxcwaterxchasxcaxchighxcsurfacexctensionxcwhenxcitxccomesxcintoxccontactxcwithxcairxc(xcallo
wingxcpondxcskatersxctoxcwalkxconxcitsxcsurface)
Whyxcisxcwaterxcdipolarxc?xc-xcanswer--
Asxcwaterxcisxcmadexcupxcofxctwoxchydrogenxcatomsxcandxconexcoxygenxcatomxc,xcthexchydr
ogenxcatomsxchavexcaxcslightlyxcpositivexcpolexcandxcthexcoxygenxcatomxchasxcaxcslightlyxcn
egativexcpolexcmakingxcwaterxcdipolar.
Hydrogenxcbondsxc-xcanswer--
Slightlyxcnegativelyxcchargedxcoxygenxcatomxcisxcattractedxctoxcthexcslightlyxcpositivelyxcch
argedxchydrogenxcatomxcofxcotherxcwaterxcmolecules.xcThexcattractionxcbetweenxcopposit
excchargesxcisxccalledxchydrogenxcbonding,xcwhichxcarexcweakxcbondsxcbutxcstrongxcinxclar
gexcnumbers.xcThisxcmakesxcwaterxcaxcmajorxccomponentxcinxccells
Hydrolysisxc-xcanswer--
Breaksxcaxcbondxcbetweenxctwoxcmoleculesxcbyxcthexcadditionxcofxcaxcmoleculexcofxcwater
Condensationxc-xcanswer--
Joinsxctwoxcmoleculesxctogetherxcwithxcthexcformationxcofxcaxcbondxcbyxcthexcremovalxcofxca
xcmoleculexcofxcwater
,Polymerxc-xcanswer--
Axcmoleculexc(xccarbohydrate,xcnucleotidexcorxcprotein)xcmadexcupxcofxcmanyxcmonomersxc
(xcsmallxcrepeatingxcunits)xcjoinedxctogetherxcbyxccondensationxcreactionsxcandxcbrokenxcd
ownxcmyxchydrolysis
Monosaccharidesxc-xcanswer--
Arexcthexcmonomersxcfromxcwhichxclargerxccarbohydratesxcarexcmadexcandxccontainxcthexc
elementsxcCxcHxcandxcO.xcTheyxcarexcsweetxcandxcsolublexcandxctherexcarexcthreexctypesxc:x
cfructosexc,xcglucosexcandxcgalactose.xcHexosexcsugarsxc(glucose)xchavexcthexcformulaxcC
6H12O6
Glucosexcisxcthexcproductxcofxcphotosynthesisxcandxcaxcmajorxcsubstratexcofxcrespirationxc,x
cdrawxcthexctwoxcstructuralxcisomersxcofxcglucosexcinxclongxcandxcshortxchandxcandxcstatexct
hexcdifferencexcbetweenxcthemxc-xcanswer--
Onxccarbonxc1xcinxcbetaxcglucosexcthexchydroxylxcgroupxc(OH)xcpointsxcupwardsxcandxcinxca
lphaxcglucosexcthexchydroxylxcgroupxcpointsxcdownxconxccarbonxc1
Sucrosexc-xcanswer--Glucosexcandxcfructose
Maltosexc-xcanswer--Glucosexcandxcglucose
Lactosexc-xcanswer--Glucosexcandxcgalactose
Howxcdoxcmonosaccharidesxcjoinxctogetherxc-xcanswer--
Byxccondensationxctoxcformxcaxcglycosidicxcbondxcbetweenxctwoxcmonosaccharidesxcandxc
axcdisaccharidexcandxcaxcmoleculexcofxcwaterxcarexcformed
Disaccharidexc-xcanswer--
Twoxcmonosaccharidesxcjoinedxctogetherxcbyxccondensationxcformingxcaxcglycosidicxcbon
d.xcTherexcarexcthreexctypesxc:xcmaltose,xcsucrosexcandxclactose.xcTheyxchavexcthexcchemi
calxcformulaxcC12H22O11
Drawxcthexchydrolysisxcofxcmaltosexcinxcstructuralxcformulaxcandxcshortxchandxcformulaxc-
xcanswer--
Testxcforxcstarchxc-xcanswer--
Addxciodinexcsolutionxctoxcthexctestxcsamplexc,xcifxcstarchxcisxcpresentxccolourxcchangesxcfro
mxcyellowxctoxcaxcblue-blackxccolour.
Testxcforxcaxcreducingxcsugarxc-xcanswer--
HeatxcwithxcBenedict'sxcreagentxc(xcblue)xcandxcifxcreducingxcsugarxcisxcpresentxcaxcbrickxcre
dxcprecipitatexcwillxcform
IssuesxcwithxcthexcBenedict'sxctestxc?xc-xcanswer--1)xcItxcisxcnonxcspecificxc-
xcdoesn'txctellxcwhichxcreducingxcsugarxcisxcpresentxc,xcaxcbiosensorxccanxcbexcusedxctoxcdet
ectxcforxcspecificxcsugarsxc
2)xcIt'sxcqualitativexcsoxccolourxcchangexcisxcbeingxcmeasuredxcsoxccan'txcobtainxcconcentra
tionxcofxcreducingxcsugarxcbutxcallowsxcanxcestimatexcforxchowxcmuchxcisxcpresentxcinxcthexcs
trengthxcofxcthexccolour
,3)xcIsxcsubjective
Howxctoxcquantifyxcresultsxconxcthexcconcentrationxcofxcunknownxcglucosexcconcentration
?xc-xcanswer--
Usexcaxccolorimeter,xcasxcaxcserialxcdilutionxcofxcknownxcglucosexcconcentrationsxccanxcbex
cmeasuredxcproducingxcaxcsetxcofxcsolutionsxcwithxcknownxcconcentrationsxc.xcThexcBenedi
ct'sxctestxccanxcbexcperformedxcwithxceachxcofxcthesexcandxcthexccolourxcintensityxcmeasure
d.xcAxcCALIBRATIONxcCURVExccanxcbexcproducedxcfromxcthexcresultsxcandxcusedxctoxcrea
dxciffxcthexcconcentrationxcofxcglucosexcinxcanxcunknownxcsolution.
Testxcforxcaxcnon-reducingxcsugarxc?xc-xcanswer--
HeatxcthexcsamplexcwithxcBenedict'sxcreagentxcandxcifxctherexcisxcnoxccolourxcchangexcaxcre
ducingxcsugarxcisxcnotxcpresentxcbutxcaxcnon-reducingxcsugarxccouldxcbe.
Heatxcaxcfreshxcsamplexcwithxcdilutexcacidxc(xcwhichxcwillxchydrolysexcthexcnonxcreducingxcs
ugarxcintoxcitsxcconstituentxcmonosaccharides).
NeutralisexcwithxcalkalixcandxccarryxcoutxcthexcBenedict'sxctestxcagainxc
Ifxcthexctestxcisxcpositivexcforxcaxcnon-
reducingxcsugarxcitxcwillxcformxcaxcbrickxcredxcprecipitate
Polysaccharidexc-xcanswer--Threexcmainxctypesxc-
xcstarchxc,xcglycogenxcandxccellulosexcwhichxcarexcchainsxcofxcmanyxcmonomersxcofxcgluco
sexcformedxcinxccondensationxcreactions.
Starchxc-xcanswer--
Starchxcisxcusedxcforxcenergyxcstoragexcinxcplantsxcandxcisxcmadexcfromxccondensationxcofxc
alphaxcglucose.
Amylose-xccompactxchelicalxcchainsxcsoxcstorexclotsxcofxcglucosexcinxcaxcsmallxcspacexc
Amylopectinxc-
xcbranchedxcchainsxcwhichxcallowxcmanyxcendsxctoxcbexcquicklyxchydrolysedxcbyxcamylasex
cenzymesxctoxcreleasexcglucosexc
Insolublexcandxclargexcsoxcnoxcosmoticxceffectsxc,xcinertxcandxccannotxcdiffusexcoutxcofxcthexc
cellsxcwhichxctheyxcarexcstoredxcinxc.
Cellulosexc-xcanswer--
Majorxccomponentxcofxcplantxccellxcwallsxcmadexcupxcofxcbetaxcglucosexcmonomerxcinxcaxcc
ondensationxcreaction.
Chainsxcofxcbetaxcglucosexcmoleculesxcformxclongxcstraightxcunbranchedxcchains.
Thesexcchainsxcrunxcparallelxctoxceachxcotherxcandxchydrogenxcbondsxcformxccross-
linkagesxcbetweenxcchains.xcThesexcmanyxchydrogenxcbondsxcprovidexchighxctensilexcstre
ngthxcwhichxcmakesxcthexccellxcwallxcrigidxcandxcpreventsxcosmoticxclysis
Hydrogenxcbondsxcalsoxcformxcstrongxcfibresxccalledxcmicrofibrilsxcwhichxcarexcgroupedxcin
toxcfibresxcwhichxcprovidexcstructuralxcsupport.
Glycogenxc-xcanswer--
Energyxcstoragexcmoleculexcinxcanimalsxcfoundxcinxcliverxccellsxcandxcinxcmusclexctissuexca
ndxcisxcmadexcfromxcthexccondensationxcofxcalphaxcglucose.xc
Compactxcsoxcstorexclotsxcofxcglucosexcinxcaxcsmallxcspacexc
Isxcquicklyxchydrolysedxctoxcreleasexcsolublexcglucosexcasxcmanyxcendsxcforxcamylasexcenz
ymesxctoxcattackxc
, Largexcandxcinsolublexcsoxcnoxcosmoticxceffectsxc,xcinertxcandxccannotxcdiffusexcoutxcofxcthex
ccellsxcwhichxctheyxcarexcstoredxcinxc.
Namexcthexc4xcinorganicxcionsxcandxcstatexctheirxcrolexc-xcanswer--
Inorganicxcionsxcoccurxcinxcsolutionxcinxcthexccytoplasmxcandxcbodyxcfluidsxc(xcbloodxc,xctissu
excfluid)xc
Hydrogenxcionsxc-
xcaffectsxcpHxclevels,xcthexchigherxcthexcconcentrationxcofxcH+xcionsxcthexclowerxcthexcpH(xc
morexcacidxc)xc
Ironxcionsxc-
xcimportantxccomponentxcofxchaemoglobinxcwhichxccarriesxcoxygenxcaroundxcthexcbodyxcin
xcthexcredxcbloodxccellsxc
Phosphatexcionsxc-
xccomponentxcofxcDNAxc,xcATPxc,xcRNAxcandxcphospholipidsxc,xcbondsxcbetweenxcphospha
texcgroupsxcstorexcenergyxcinxcATPxc
Sodiumxcionsxc-
xcinvolvedxcinxcthexcabsorptionxcofxcglucosexcandxcaminoxcacidsxcinxccoxctransportxcinxcthexcs
mallxcintestine
Aminoxcacidsxc-xcanswer--
Arexcthexcmonomersxcfromxcwhichxcpolypeptidesxcarexcmade.xcProteinsxcarexcmadexcupxco
fxconexcorxcmorexcpolypeptidexcchains.xcAllxcaminoxcacidsxccontainxcthexcelementsxcCxcHxcO
xcandxcNxcandxcarexcmadexcupxcofxcanxcaminoxcgroupxc(NH2)xc,xcaxccarboxylicxcacidxcgroupxc(
COOH)xcandxcaxcvariablexcgroupxc(R)
Whatxcisxcaxcconjugatedxcproteinxc?xc-xcanswer--Axcproteinxcwithxcaxcnon-
proteinxcchemicalxcgroupxcattached
Drawxcthexcstructurexcofxcanxcaminoxcacidxc-xcanswer--
Howxcmanyxcaminoxcacidsxcarexctherexcthatxcarexcsharedxcinxcallxcorganismsxc?xc-xcanswer--
20xcaminoxcacidsxcthatxcdifferxcbyxcaxcdifferentxcvariablexcgroup.
Dipeptidexc-xcanswer--
Twoxcaminoxcacidsxcjoinxctoxcformxcaxcdipeptidexcandxcaxcpeptidexcbongxcisxcformedxcbetwe
enxcthexcaminoxcacidsxcbyxcaxccondensationxcreaction.
Drawxcthexcformationxcofxcaxcdipeptidexcfromxctwoxcaminoxcacids?xc-xcanswer--
Describexcthexcproteinxcstructurexc?xc-xcanswer--Primaryxcstructurexc-
xcsequencexcofxcaminoxcacidsxcinxcaxcpolypeptidexcchainxc
Secondaryxcstructurexc-
xcfoldingxcofxcpolypeptidexcchainxccausingxchydrogenxcbondsxctoxcformxcbetweenxcaminoxca
cidsxccausingxcthexcformationxcofxcanxcalphaxchelixxcorxcaxcbetaxcpleatedxcsheetxc
Tertiaryxcstructurexc-
xcthexcfurtherxcfoldingxcofxcthexcsecondaryxcstructurexcwhichxcisxcheldxcintoxcshapexcbyxcbon
dsxce.g.xchydrogen,xcionicxcandxcdisulphide.xcBondsxcformxcbetweenxcRxcgroupsxcofxcamin
oxcacidsxcformingxcaxc3Dxcstructurexcandxcisxcthexcfinalxcstructurexcofxconexcpolypeptidexcch
ainxc
