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Lab3:CellularRespirationCellrespirationreferstotheprocessofconvertingthechemicalenergyoforganicmoleculesintoaformimmediatelyusablebyorganisms.Glucosemaybeoxidizedcompletelyifsufficientoxygenisavailableandissummarizedbythefollowingreaction:
𝐶𝐶"𝐻𝐻$%𝑂𝑂" + 6𝑂𝑂% 𝑔𝑔 → 6𝐶𝐶𝑂𝑂% 𝑔𝑔 + 6𝐻𝐻%𝑂𝑂 + 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑔𝑔𝑒𝑒
Allorganisms,includingplantsandanimals,oxidizeglucoseforenergy.Often,thisenergyisusedtoconvertADPandphosphateintoATP.Itisknownthatpeasundergocellrespirationduringgermination.Dopeasundergocellrespirationbeforegermination?Usingyourcollecteddata,youwillbeabletoanswerthisquestionconcerningrespirationandnon-germinatedpeas.UsingtheCO2GasSensor,youwillmonitorthecarbondioxideproducedbypeasduringcellrespiration.Bothgerminatedandnon-germinatedpeaswillbetested.Afteryourpreliminaryinvestigation,youwillinvestigatehowvariousfactorsmayinfluencetherateofcellularrespiration.
OBJECTIVES
Inthisexperimentyouwill
• UseaCO2GasSensortomeasureconcentrationsofcarbondioxideduringcellrespiration• Determinewhethergerminatingpeasandnon-germinatingpeasrespire• Comparetheratesofcellrespirationingerminatingandnon-germinatingpeas• Designyourownexperimentstomeasureratesofrespirationofdifferentseedsandorganismsas
wellastheeffectofseveralvariablesincludingsalinity,germinationtime,andtemperature
MATERIALS
LabQuest2 GerminatedandNon-germinatedPeasVernierCO2GasSensor VariousSeeds(bothGerminatedandNon-germinated)250mLRespirationChamber IceThermometer HotWaterBathCrickets Mealworms
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PROCEDURE
1. EnsureyourCO2GasSensoryisproperlyconnectedtotheLabQuest2andchoose“New”fromtheFileMenutosetupanewexperiment.
2. RecordtheroomtemperatureinTable1.Askyourinstructorforthecurrenttemperature3. Preparefordatacollectionbychangingthecollectionmodeto“TimeBased”.Settheintervalto4
seconds/sampleandthedurationto300secondsasinthepicturebelow:
4. Obtain25germinatedpeasandblotthemdrybetweentwopiecesofpapertowel.Placethe
germinatedpeasintotherespirationchamberasshowninthefigureonthepreviouspage5. PlacetheshaftoftheCO2GasSensorintheopeningoftherespirationchamberasinFigure16. Waitonetotwominutes,thenstartdatacollection.Datawillbecollectedfor5minutes.7. Whendatacollectionhasfinished,agraphofcarbondioxidegasvs.timewillbedisplayed.8. RemovetheCO2GasSensorfromtherespirationchamber.Returnthepeastothecontainerwhere
youfoundthem9. UseanotebookornotepadtofanairacrosstheopeningsintheprobeshaftoftheCO2GasSensor
for1minute10. Shaketherespirationchamberaroundforaminutetocompletelyrefreshtheairinsidethe
chamber11. Repeatsteps4thru10usingnon-germinatedpeas12. Performalinearregressiontocalculatetheratesofrespiration
a. Gotothegraphanddisplayallrunsb. ChooseCurveFitfromtheAnalyzemenu.Thenselectyourfirstrun(Germinated)c. SelectLinearfortheFitEquation.Thelinear-regressionstatisticsforthesetwodata
columnsaredisplayedfortheequationintheform
𝑒𝑒 = 𝑚𝑚𝑚𝑚 + 𝑏𝑏
Wherexistime,yisCO2concentration,mistheslope,andbisthey-intercept
d. Entertheslope,m,astherateofrespirationinTable2onthenextpage13. Performstep12againforyoursecondrun(non-germinated)
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DATA
OPENINQUIRY
Nowthatyouhavedataforbothgerminatedandnon-germinatedpeas,whataresomefactorsthatmayeffectthatratesofrespirationofpeas/seeds?Designyourexperimentstotestoneormorevariablesincludingthingssuchastemperature,timeofgermination,light,typeofseeds,etc.Afterdeterminingwhichvariablesyouwouldliketotest,comeupwithahypothesisandrunyourexperiment!Besuretorecordalloftherelevantdatainyourownlabnotebook.
QUESTIONS
1. Doyouhaveevidencethatcellrespirationoccurredinpeas?Explain.
2. Whatistheeffectofgerminationontherateofcellularrespirationinpeas?
3. Whydogerminatedpeasundergocellrespiration?
4. Wouldyouconsidernon-germinatedseeds“Alive”?
5. Listthreefactorsthatcouldpossiblyaffecttherateofcellularrespiration.
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SAVINGANDEXPORTINGYOURDATA
1. Onceyouhavecompletedacquiringallofyourdata(bothguidedandopeninquiry)andperformedthelinearregressiononallofyourdataruns,select“File”,“Save…”,andthengiveyourfileanameusingthefollowingformat:
MMDDYY_School_LQ###(ex.112119_OB_LQ202)2. Select“Save”andyourfilewillbesaved.Youwillthenbereturnedtothemainscreen3. Select“File”againandthistimeselect“Email”asshownbelow:
4. Select“Graph…”andthenenterthefollowingemailaddress:
5. Onthe“Subject”line,enteryourschool,LabQuestNumber,andexperimentnameusingthe
followingformat:School_LQ###_RespGraph.Itshouldlooksimilartheoneintheimageabove.Onceyouarefinished,select“Send”
6. Repeatsteps3-5exceptthistimeselect“Email”and“TextFile…”instead.Underthesubjectline,replacetheword“Graph”with“Data”.Itshouldlooksomethinglike“BLA_LQ202_RespData”
Graphoutputexample
Textoutputexample
SCHOOLCODES
OB=J.D.O’Bryant
KD=KennedyHCA
TB=TechBostonAcademy
BLA=BostonLatinAcademy