《AP生物-LAB-5-WRITE-UP》由会员分享，可在线阅读，更多相关《AP生物-LAB-5-WRITE-UP（7页珍藏版）》请在金锄头文库上搜索。
1、APBIOLOGYCellRespirationLabWrite-upOBJECTIVES?Tounderstandrespiration,dormancy,andgermination.?Knowhowarespirometerworksintermsofthegaslaws;thegeneralprocessesofmetabolisminlivingorganisms;?Howtherateofcellularrespirationrelatestotheamountofactivityinacell.?Calculatetherateofcellrespirationfromexper
2、imentaldata?Relategasproductiontorespirationrate?Testtherateofcellularrespirationingerminatingversusnongerminatedseedsinacontrolledexperiment;and?Testtheeffectoftemperatureontherateofcellrespirationingerminatingversusnongerminatedseedsinacontrolledexperiment.PROCEDURE?Setuptwowaterbaths,oneatroomtem
3、perature,theotheroneat10degreeCelsius?Forrespirometer1,Countout50germinatingpeasandplacethemintothegraduatedcylinder.Forrespirometer2,putin50drypeasand110plasticbeads.Forrespirometer3,onlyputin150plasticbeads.(nowthevolumesoftherespirometersshouldbethesame)Andthefirstsetofrespirometerisready.Prepare
4、anothersetofgerminatingpeas,driedpeasplusbeads,andplasticbeads.Toassemblethesixrespirometers,obtainsixvials,eachwithanattachedstopperandpipette.Placeasmallpieceofcottoninthebottomofeachvialand,usingadropper,moistenthecottonwith15%KOH.Makesurethattherespirometervialsaredryontheinside.DonotgetKOHonthe
5、sidesoftherespirometer.PlaceasmallwadofnonabsorbentcottonontopoftheKOH-soakedabsorbentcotton.Placethefirstsetofgerminatingpeas,drypeasplusbeads,andbeadsinvials1,2,and3.Placethesecondsetinvials4,5,and6,respectively.Insertthestopperfittedwiththecalibratedpipette.Placeaweightedcollaroneachendofthevial.
6、Makeaslingofmaskingtapeattachedtoeachsideofeachofthewaterbathstoholdthepipettesoutofthewaterduringanequilibriumperiodofsevenminutes.Vials1,2,and3shouldrestintheroomtemperaturebathandtheothervialsshouldrestinthe10degreeCelsiuswaterbath.?Aftertheequilibriumperiodofsevenminutes,immerseallsixrespiromete
7、rentirelyintheirbaths.?Allowtherespirometerstoequilibrateforthreemoreminutesandthenrecord,tothenearest0.01mL,theinitialpositionofwaterineachpipette.Checkthetemperatureinbothbathsandrecorditinthedatatable.Every5minutesfor20minutes,takereadingsofthewaterspositionineachpipetteandrecordthedata.DATATemp(
8、C)Time(min)BeadsAloneGerminatingPeasDrypeasandBeadsReadingtimeXDiff.ReadingtimeXDiff.CorrectedDiff.ReadingtimeXDiff.CorrectedDiff.10C05.3-5.3-5.3-55.30.05.30.00.05.30.00.0105.30.05.0.30.35.10.20.215RoomTemp05.6-5.4-5.7-55.60.05.1.3.35.70.00.0105.60.04.9.2.25.50.20.2155.60.04.7.2.25.6-0.10.10303i7。/
9、1Z_510Time (min)Oxygen consumption ovar time86 4 L I o c ptDEnsuco U86AX。2.o.Geirrnnating Peas 4 0 CDry peas and Beads IOCGerminatingat room temp Dry peas plus beads at room temp15Fromthedatawecollectedandthegraphabove,wewanttofindbetweentherateoftherespirationandthetemperature,aswellasthedifference
10、inrespirationratebetweengerminatingpeasanddrypeas.Thisactivityusesanumberofcontrols,byusingtheidealgaslaw,PV=nRT,wekepttheairpressureandthevolumeofmaterialsineachrespirometerconstant.Thatway,wecanfigureouttheeffectoftemperatureontherespiration.Watermovedintotherespirometerspipettesbecausepressuredec
11、reasedwhentheamountofoxygenwasdecreased(orconsumed).Bymeasuringtheamountofwaterinthepipette,wecanknowtheamountofoxygenconsumedbythepeas.Thevialhadtobecompletelysealedsothatgasescouldntescapeandwatercouldntleakintotherespirometer.Thegraphshowedthatasthetimegoeson,theamountofoxygenconsumedincreases.Dr
12、ypeasstartedconsumingoxygenslowerthangerminatingpeas.Andgerminatingpeasgenerallyconsumedmoreoxygenthandrypeas.Italsotellsusthattheamountofoxygenconsumedisgreaterinwarmerwaters,forbothgerminatinganddrypeas.ConditionShowCalculationsHereRate(mLO2/minute)GerminatingPeas/100C(0.3-0.0)/100.03mL/minGermina
13、tingpeas/Roomtemperature(545.7)/150.047mL/minDryPeas/100C(0.2-0.0)/100.02mL/minDryPeas/RoomTemperature(5.7-(5.5+5.6)/2)/150.01mL/minThistableshowedthatthegerminatingpeasinroomtemperaturehaveahighestrespirationrateoverall,whichmeansgerminationcanincreasethepeaseedsrespirationeffectively.Andthedrypeas
14、didntturnoutthewayweexpected,whichwethoughttheratewassupposedtobehigheratawarmertemperature.Instead,theyhaveahigherrateat100C.Itisnecessarytocorrectthereadingsfromthepeaswiththereadingsfromthebeads,becausethebeadsservedasacontrolgroup.Itsimportanttofindthechangeinrateofrespirationbycomparingwiththeb
15、eads.ThepurposeofKOHisthisexperimentistoremovetheC02,sothatthepressureofCO2wontaffectthereading.possiblegraphfor口2consumptionbygerrnfnatingpeasastemperaturecontinuesincreasingThisgraphhereshowsthepredictionoftherateofoxygenconsumptionastemperatureincreases.Theconsumptionwoulddropdramaticallybecausewhenthetemperaturegetstoohigh,theenzymewillbede
