digestive system i with answer[1]

1、F.4BiologyexperimentDigestionIPage1F.4BiologyExperimentIName:_______________________Class:______()TASK1:1.Perfmasimpleexperimenttoshowtheneedfdigestionoffood.2.Tieaknotatoneendofadialysistubing.Fillthetubingwithequalvolu

2、mesofstarchsolutionglucosesolution.3.Tietheotherendofthetubingmakesurethetubingdoesnotleak.Washtheoutsideofthetubingwithdistilledwater.4.Immersethetubinginaboilingtubeofwater.5.Testthewateroutsidethetubingimmediatelyfsta

3、rchglucoseusingiodinesolutionClinstixpaperrespectively.Perfmthesametestsafter45minutes.Questionsfdiscussion:1.Inthespacebelowdrawatabletoshowtheresultsofallthetestsdoneduringtheexperiment.(4marks)2.Explainwhyitisnecessar

4、ytorinsetheoutsideofthetubingwithdistilledwaterbefeputtingitintotheboilingtube.(2marks)Toremoveanystarchglucosesolutionstickingonthesurfaceofthedialysistubing(1).Thiscanpreventthecontaminationofwaterinthebeaker.(1)Iodine

5、TestClinstixPaperTestAttime0BrownyellowPinkAfter45minsBrownyellowPurpleStarchglucosesolutionstarchsolutionF.4BiologyexperimentDigestionIPage23.Inthisexperimentthemainconceptis:Aivelypermeablemembraneonlyallowssmallmolecu

6、lestopassthrough.(a)Whichpartofacellisivelypermeable(1mark)Thecellmembrane(b)Suggesthowtheprocessesoffooddigestionabsptionarerelatedtotheivelypermeabilityofthepartyouhavementionedinpart(a).(3marks)Largefoodmoleculessucha

7、sstarchhavetobedigestedtosmallermoleculessuchasglucose(1)whicharesmallenoughtopassthroughthemembraneofthecellsofthesmallintestine(1).Afterthatthesmallfoodmoleculescanthroughthewallofthebloodvesselsentertheblood.(1)4.Repe

8、attheexperimentbyaddingequalvolumeofstarchsolutionamylasesolution.After45minutestestthewaterintheboilingtubeusingiodinesolutionBenedict’ssolutionclinstixpaper.(a)Inthespacebelowtabulatetheresultsofthethreetestsattheendof

9、theexperiment.(3marks)(b)Referringtotheresultsinpart(a)whatconclusioncanbedrawn(1mark)Thewaterinsidethetubingcontainsreducingsugarsbutnotstarchglucose.(1)(c)Inthespacebelowwriteawdequationtoshowthedigestionofstarchbyamyl

10、ase.(2marks)amylaseStarch????????maltose(d)Alivingcelldoesnotsteglucose.SuggestTWOpossiblereasonsfthisfinding.(4marks)Glucoseissmallinsize(1).Ifglucosemoleculesarestedatahighconcentrationinsidelivingcellstheywilldiffuseo

11、utbelost.(1)Whenlargeamountofglucosedissolvesinthecytoplasmitwilllowerthewaterpotentialofthecell.(1)Watermovesintothecellsbyosmosiseventuallytheyburst.(1)IodineTestClinstixPaperTestBenedict’stestBrownyellow(ve)Pink(ve)Gr