毛細(xì)管基礎(chǔ)知識(shí)課件

ActivityBookActivityBookonechapter3(PART2of2PARTSp.41to58)suggestedanswer,modifiedfromapublished(OUP)source.(ver.2007)Osmosis3.6Studyofosmosisinnon-livingmaterialQuestions1 Whyisacapillarytube(毛細(xì)管)

used?

Itssmall

diameter(ie.beingnarrow,窄)givesafasterchangeinliquidlevelinashorttime.3.62 Whyshouldwerinsetheoutsideofthetubingwithwaterbeforesettinguptheapparatus?

Sucrosemoleculesontheoutsideofthetubingcanchangetheconcentrationofthesolutioninthebeaker.Rinsing

clearsawaysucrosethatmightbeaddedduringpouring.3.63a

EXPLAINthechangeintheliquidlevel inthecapillarytubeoftheexperimental

set-up.Thereisanetwatermovement

fromdistilledwatertosucrosesolution.

3b

Nametheprocess(過(guò)程)thatcausesthe changeintheliquidlevel.Osmosis.3.63c Whichpropertyofthetubingenablesthe aboveprocesstooccur?Differentialpermeability,orsemi-permeability.

3.6a amoreconcentratedsucrosesolutionisputinthetubing?Theliquidlevelwillrise

fasterandhigher.4 Whatwillhappentotheliquidlevelinthecapillarytubeifb distilledwaterisputinthetubingandsucrosesolutionisputinthebeaker?Theliquidlevelwilldropandthetubingwilleventuallyshrink.Learn:osmosisnetmovementsemi-permeablesucrosemoleculedialysistubingrise/drop/fall3.7Studyofosmosisinlivingplantcells1 Whyisthelowerepidermisinsucrosesolutioncoveredbyacoverslipbeforebeingobserved?Topreventtheevaporationof sucrosesolution,whichmay changeitswaterpotentialand affecttheresults.Thisalsokeepstheobjective

lensofthemicroscopeclean.Learn:Changingtheconcentrationcanaffecttheresult.(動(dòng)詞)Theeffectofpollutionisbad.(名詞)3.73 Doallcellschangeatthesamerate?Why?No.Thisisbecausetheconcentrationofthecellcontent(orwaterpotentialofeachcell)varies

變化(OR,notallcellshavethesameosmoticconcentration).

3.7

Whatconclusionabouttheosmoticeffectsofthesurroundingfluidonplantcellscanyoudrawfromthispractical?Whenthesurroundingfluidhasalowerwaterpotentialthantheplantcells,waterleaves離開

thecells,whichwilleventuallyplasmolyze(質(zhì)壁分離)andbecomeflaccid.Aswaterpotentialofthesurroundingfluidincreases,waterwillenterthecellsagain.Thecytoplasmexpandstofillthewholecell.Thecellsthenbecometurgid.Conclusion3.8Studyofosmosisinlivingplanttissues1 Whyisitnecessarytopeel(去皮)

thepotatoes?

Theskinofthepotatoesismadeupofdeadcells

and

arefullypermeable.Peelingofftheskinmakesallthepotatocellshaveasemi-permeablemembraneforfaircomparisonintheexperiment.3.83 ExplainanychangeintheliquidlevelinpotatocupX.NochangeisobservedintheliquidlevelofpotatocupX.Thoughlivingpotatocellsaredifferentiallypermeable,nowaterpotentialgradientexists

BETWEENBOTHSIDES

ofthecup.Thereforeosmosisdoesnotoccur.

3.84 ExplainanychangeintheliquidlevelinpotatocupY.

TheliquidlevelinpotatocupY

rises.SincelivingpotatocellsaredifferentiallypermeableandawaterpotentialgradientexistsBETWEENBOTHSIDESOFTHECUP,osmosisoccurs.Learn:Awaterpotentialgradientexistsbetween

AandB.Learn:SubstanceXdiffusesacross

barrierY

andpassesfrom

AtoB.XAYB基本句法3.8

Whatconclusionaboutosmosisinlivingplanttissuescanyoudrawfromthispractical?Livingplanttissuesaredifferentiallypermeable.Whensolutionswithdifferentwaterpotentialareseparatedbylivingplanttissues,osmosistakesplace.(Tobecontinued.)Conclusion3.8However,thedifferentialpermeabilityofcellmembraneswillbelostifthetissuesaredead,i.e.cellmembranesarefullypermeabletoallsolutes.Therefore,osmosiscannottakeplaceacrossdeadtissues.……continuedfrompreviouspageLearn:Experimentalset-upControlset-upFactorVariableCompareAwithBForcomparisonbetweenAandB3.92 Explainanychangeintheliquidlevelinset-upA.Distilledwaterhasahigherwaterpotentialthanconcentratedsucrosesolution,sothereisanetmovementofwaterfromdistilledwatertoconcentratedsucrosesolutionthrough

thedifferentiallypermeableanimaltissues

byosmosis.3.10Examinationofdifferentlevelsoforganizationinorganisms(組織梯階)ResultsLevelFloweringplant(e.g.Hibiscus)Mammal(e.g.rat,human)OrganExamples:

rootstemleafflowerExamples:heartstomachintestinelung3.10ExaminationofdifferentlevelsoforganizationinorganismsResultsLevelFloweringplant(e.g.Hibiscus)Mammal(e.g.rat,human)SystemExamples:transportsystem(vasculartissuesinroot,stem,flowerandfruit)Examples:

digestivesystem

respiratorysystem

excretorysystem

reproductive

system3.1ApplicationofenzymesincommercialproductsandindustrialprocessesQuestions1Whydidthemilkinsidethebagcoagulate?Thebagwasmadefromasheep’sstomachandcontainedrennin.Itisthisenzymethatcausedthecoagulation凝結(jié)ofmilk.2

Explainhowthehotweatherhadspeededupthecoagulationofmilkinsidethebag.Underhotweather,thekineticenergyofthemilkproteinandrenninmoleculesincreaseandthemolecules

movefaster.Thisincreasesthechancetheyhiteachother(分子碰撞機(jī)會(huì)多了)andformtheenzyme-substratecomplexes.Coagulationofmilkwasthereforespeedsup.3.1Concept(tolearn):Particlesvibrate&hiteachother!3Apartfromtheweather,suggestanotherfactorthathadspeededupthecoagulationofmilkinsidethebag.Themovementofthecamelwhichproducedastirringeffect

攪拌作用.3.13.1Phillipsheadscrewdriversandstraightbladescrewdrivers1WhichkindsofREACTIONSdotheunscrewingandreassemblingofstripsrepresentrespectively?Theunscrewing(扭鬆螺絲)ofstripsrepresentsacatabolicreaction,whereasthereassembling(重新砌作)ofstripsrepresentsananabolicreaction.Activity2 CanthestripsbeunscrewedonlywithPhillipsheadscrewdrivers(十字頭螺絲刀)orstraightbladescrewdrivers(一字頭螺絲刀)?Why?Straightbladescrewdriversbecausetheirshape

fitsthatofthescrews.3.1Activity3 Whichproperty(特性)ofenzymesisillustratedin2?Enzymesarespecificintheiractions.3.1Activity4 Canthestripsbereassembledwiththeworn-out(磨損)straightbladescrewdriver?Why?No.Itisbecauseitsshapenolongerfitsthatofthescrews.3.1Activity5 Whichpropertyofenzymesisillustratedin4?Enzymesaredenaturedathightemperaturesandtheylosetheirfunctions.Exercise3Multiple-choicequestionsQuestionNo.AnswerQuestionNo.Answer1

6

2

7

3

8

4

9

5

10

CCAACDCADDStructuredquestions1a Whattypeofmetabolicreactionisshown,anabolismorcatabolism?Giveareasonforyouranswer. Anabolism(0.5m)

Itshowsabuilding-upprocess.(0.5m)1b WhatdoW,X,YandZrepresentinanenzymaticreaction?W:enzyme(0.5m)

X:substrate(0.5m)

Y:substrate(0.5m)

Z:product(0.5m)Exercise31c i WhatisthefunctionofW?Itservesasabiologicalcatalystwhichspeedsupthereaction.(1m)1c ii ListtwopropertiesofW.DenaturedathightemperatureTemperatureandpHsensitive(ie.Easilyaffectedbythetwofactors)ReusableSpecificinaction (Any2,1meach)Exercise31d i Givetwofactorsthatcanaffectthe aboveprocess?pH(0.5m)andtemperature(0.5m).1d ii Explainhowthesefactorsaffectthe aboveprocess.

ChangeinpH:Italterstheshapeofenzyme’sactivesitehence,affectstheactivityofenzyme.(1m)(Tobecontinued.)Exercise3Temperatureabovetheoptimumtemperature:Italterstheshapeofenzyme’sactivesite

(0.5m).Denaturationwilloccurifextremelyhightemperatureisreached.(0.5m)……continuedfrompreviouspageExercise3Temperaturebelowtheoptimumtemperature:Theenzymewillbeinactivated.(1m)2a Withreferencetothepropertiesofenzymes,statethreeadvantagesofusingenzymesinindustry.lEnzymesarebiodegradable,thustheycauselesspollutiontotheenvironment.(1m)

lEnzymesarespecificinaction,thuspureorspecificsubstancecanbeproduced.(1m)lEnzymesarereusable,thusthecostofproductioncanbereduced.(1m)Exercise32b Whyisenzymeregardedasabiologicalcatalyst?Enzymesaremadebylivingcells(0.5m)andabletospeedupchemicalreactions(0.5m)Exercise32c i Whatkindofenzymeisusually presentinwashingpowder?Protease/Lipase

(Any1,1m)Exercise32c ii Whycanthewashingpowder containingenzymesbeusedforcotton butnotforsilkandwool?Silkandwoolareanimalfabricsthataremainlymadeupofproteins

(0.5m).Theywillbedigestedbyprotease

(0.5m).Cottonisplantfabricsthataremainlymadeupofcellulose(0.5m).Itwillnotbedigestedbyprotease(0.5m).絲,羊毛2d Isitsuitabletousewarmwater(e.g.60℃)towashclotheswiththiskindofwashingpowder?No.(1m)

Itisbecausetheenzymeswillbedenaturedatsuchhightemperature.

(1m)However,newlydevelopedenzymesdesignedbygeneticengineeringmaybemoretolerant.Exercise33a Whatisthedifferencebetweenthecellsbeforeandaftertreatment?Cellmembranesdetachfrom(離開)thecellwalls(orcellsbecomeplasmolysed).(1m)Exercise33b i Whatisthepossibletreatmentdone tocellsinphotoAtobecomethosein photoB?Thecellsareimmersedin(浸在)ahypertonicsolution.(1m)Exercise33b ii

Describeandexplainwhathappens duringthetreatment?Thereisanetwatermovementfromthecellstothesolutionoutsidebyosmosis(1m).Itisbecausethewaterpotentialinsidethecellsishigherthanthatofthesolutionoutsidethecells(1m).3c Whichpartofthecellsregulatesuchprocess?Cellmembrane(1m)3d IfthetissueinphotoAisboiled,whathappenstothecellsafterthetreatment?Explainyouranswer.Thecellsremainunchanged

(1m).Itisbecausethedifferentialpermeabilityofthecellmembraneisdestroyedduringboiling(1m).Exercise33e Otherthanthemethodyouansweredinbi,whattreatmentcanbedonetogetthesameresultshowninphotoB.Placethetissueinadryplace.(1m)Exercise3Exercise33f WhatwillhappenifdistilledwaterisaddedtothecellsinphotoA?Explainyouranswer.Thecellsremainunchanged

(1m).Itisbecausetherigid(strong)cellwalls

preventthenetmovementofwaterfromthesolutionoutsideintothecel