AQA A level Biology Revision questions and answers 100% verified.

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AQA A level Biology Revision questions and
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answers 100% verified. x x

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Describe xhow xyou xwould xuse xa xbiochemical xtest xto xshow xthat xa xsolution xcontained xa
xnonreducing xsugar, xsuch xas xsucrose. x[3] x- x xcorrect xanswer. x x x,first xreducing xsugars

xtest; xboil xwith xdilute xHCl xacid xthen xNeutralise xwith xNaHCǑ, xadd xbenedict xand xheat

xto x95 xdegrees xC xbrick xred xppt xforms xif xreducing xsugar xis xpresent x
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Describe xa xchemical xtest xyou xcould xcarry xout xto xshow xthat xa xpiece xof xcoconut
xcontains xlipids. x[3] x- x xcorrect xanswer. x x x(Crush xin) xethanol x/ xalcohol; xAdd x(to) xwater

x(Order xof xadding xis xcritical xfor xthis xpoint); xEmulsion x/ xwhite xcolour x
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Explain xwhat xis xmeant xby xa xpolymer. x[1] x- x xcorrect xanswer. x x xMolecule) xmade xup xof
xmany xidentical/similar xmolecules/monomers/ xsubunits; x
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Name xthe xreaction xwhich xoccurs xwhen xstarch xis xbroken xdown xinto xmaltose. x[1] x- x
xcorrect xanswer. x x xHydrolysis x
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What xis xthe xformula xfor xlactose? x[2] x- x xcorrect xanswer. x x xC12 x; xH22Ō1 x
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Describe xhow xβ-glucose xmolecule xdiffers xfrom xa xmolecule xof xα-glucose. x[1] x- x
xcorrect xanswer. x x xH xat xtop xright xend x(instead xof xOH) x/ xOH xat xbottom x(carbon x1) x
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Show xtwo xways xin xwhich xthe xstructure xof xcellulose xis xdifferent xfrom xthe xstructure xof
xstarch. x[2] x- x xcorrect xanswer. x x xStarch x1,4 xand x1,6 xbonds x/ xbranching xCellulose x1,4

xbonds x/ xno x1,6 xbonds x/ xstraight; xstarch xAll xglucoses x/monomers xsame xway xup

xcellulose x

Alternate xglucoses xupside xdown; xstarch xHelix x/ xcoiled/compact xcellulose xStraight;
xStarch xmonomer xAlpha xglucose xCellulose xmonomer xBeta xglucose x
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Describe xthe xstructure xof xstarch xand xexplain xhow xits xstructure xis xrelated xto xits
xfunction. x

[3] x- x xcorrect xanswer. x x xFormed xfrom xα xglucose; xJoined xby xcondensation/ xby xthe
xremoval xof xa xwater xmolecule/ xglycosidic xbonds; xBetween x(carbons) x1 xand x4 x(and x1

xand x6); xCoiled xchain; xcompact; x(Allows) xstorage xof xlarge xamount xin xa xsmall xspace;

xInsoluble xso xhas xno xeffect xon xosmosis/water xpotential; xBranches; x(Allows) xrapid

xbreakdown/release xof xglucose x/ xhydrolysis; x
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The xstructure xof xa xphospholipid xmolecule xis xdifferent xfrom xthat xof xa xtriglyceride.
xDescribe xhow. x[2] x- x xcorrect xanswer. x x x triglyceride xhas xthree xfatty xacids xand

xphospholipid xhas xtwo; xno xphosphate xgroup xpresent xin xtriglyceride xbut xpresent xin

xphospholipid. x

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What xis xan xunsaturated xfatty xacid? x[1] x- x xcorrect xanswer. x x xSome x/ xtwo xcarbons xwith
xonly xone xhydrogen x/ x(double xbonds) xbetween xcarbon xatoms x/ xnot xsaturated xwith

xhydrogen; x
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Describe xthe xstructure xof xcellulose xand xexplain xhow xits xstructure xis xrelated xto xits
xfunction. x

[3] x- x xcorrect xanswer. x x xAlternate xβ-glucose xrotated x180o, xlong xstraight xchains, xMany
xhydrogen xbonds xjoin x(polysaccharide) xchains/molecules xto xeach xother x/ xmakes

xmicrofibrils x/ xgives xtensile xstrength; x
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Which xelements xare xfound xin xproteins? x[1] x- x xcorrect xanswer. x x xCarbon, xhydrogen,
xoxygen, xnitrogen x(sometimes xsulphur) x
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Describe xhow xyou xwould xuse xa xbiochemical xtest xto xshow xthat xa xsolution xcontained
xprotein. x[2] x- x xcorrect xanswer. x x xBiuret x/ xalkali x+ xcopper xsulphate; x

Lilac/purple/mauve/violet; x
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Which xbonds xare xfound xin xa)Primary xstructure x[1]b)Secondary xstructure x[1] xc)Tertiary
xstructure x[2] x- x xcorrect xanswer. x x xa)Peptide xb) xHydrogen x(and xpeptide) xc)Ionic,

xdisulphide xbridges, xhydrophobic xinteractions x(hydrogen xand xpeptide) x
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Explain xhow xa xchange xin xthe xprimary xstructure xof xa xglobular xprotein xmay xresult xin xa
xdifferent xthree-dimensional xstructure. x[3] x- x xcorrect xanswer. x x xSequence xof xamino

xacids xchanges; xtertiary xstructure xchanges/folds xin xa xdifferent xway; xbonds xform xin

xdifferent xplaces x(not xpeptide); x
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Describe xhow xtwo-way xchromatography xis xcarried xout. x[2] x- x xcorrect xanswer. x x xRun
xchromatogram xthen xturn xthrough x90/right xangle; xWith xa xdifferent xsolvent; x
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Explain xthe xadvantage xof xusing xtwo-way xchromatography xto xseparate xshort
xpolypeptides. x[2] x- x xcorrect xanswer. x x xSpreads xspots/polypeptides xout xmore/ xmake

xsure xspot xonly xcontains xone xsubstance; x
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Explain xhow xinhibitors xaffect xthe xrate xof xenzyme-controlled xreactions. x[6] x- x xcorrect
xanswer. x x xStatement xabout xtwo xtypes, xcompetitive xand xnon-competitive; xCompetitive:

xSimilar xshape xto xsubstrate;Inhibitor xcan xenter/bind xwith xactive xsite x(of

xenzyme);Noncompetitive: xAffect/bind xto xenzyme xother xthan xat xactive xsite; xDistorts

xshape xof xactive xsite; xInhibitors: xPrevent xentry xof/binding xof xsubstrate xto xactive xsite;

xTherefore xfewer/no xenzyme-substrate xcomplexes xformed; x
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Describe xand xexplain xhow xan xincrease xin xtemperature xaffects xthe xrate xof xan xenzyme
xcontrolled xreaction. x[5] x- x xcorrect xanswer. x x xRate xof xreaction xincreases; xIncreasing

xtemperature xincreases xrate xof xmovement xof xmolecules/ xkinetic xenergy; xCollide xmore

xoften/substrate xenters xactive xsite xmore xoften/more xenzyme-substrate xcomplexes

xformed; xUp xto xoptimum; xRate xof xreaction xdecreases; xHigh xtemperatures xcause

xdenaturation/loss xof xtertiary xstructure/3D xstructure; xBy xbreaking xspecified xbonds x(not

xpeptide xbond); xActive xsite xaltered/substrate xcannot xbind/fit/ x
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