Photosynthesis and Respiration

Photosynthesis and Respiration

Experiment

Photosynthesisand Respiration

Photosynthesisis the process solely responsible for the production of energy whichfacilitates the production of food. Respiration, on the other hand isa process that involves the purification of the atmosphere and thusunnecessary gases are eliminated. The two processes explain theinterrelationship that is present between animals and the plants analso explains the importance of various elements in the ecosystem.

Observations

Data Table 1: Rf Value Comparison for Chlorophyll Pigments

Chlorophyll

Pigment

Observed

Color

Distance to top of pigment, mm

Rf

Other Students’ Rf

Average

# of Rf Results Averaged from other Students (N)

Top of Solvent

Front

NA

100

1.0

1.0

1.0

Carotenoids

Rusty brown

96

0.96

.74

.92+0+1.3

Xanthophylls

yellowish

40

0.40

.21

.45+.10+.17

Chlorophyll a

Green

68

0.68

1.21

.58+.55+2.5

Chlorophyll b

Green

24

0.24

4.02

.42+.30+11.6

Distancetotopofpigment,mm:Measurefromwherethetopofthesolventextractlevel

Intersectedthepaperchromatographtothetopmostlevelofthecolor.Thenmeasurethis

distancetothe topof the solventfrontand record.

Data Table 3: Gross Photosynthesis in Elodea

Rates

Distance of travel, mm

Net Photosynthesis Rate over 10 minutes

= mm of movement from marked beginning point on bent

tube to end point after 10 minutes

16

Respiration Rate over 10 minutes

= mm of movement from marked end point on bent tube

toward beginning point after 10 minutes

14

Gross Photosynthesis over 10 minutes

(= mm Net Photosynthesis + mm Respiration)*

26

Rate of Photosynthesis over one hour

(= Gross Photosynthesis ÷ 10 minutes x 60 minutes)

156

*Wasrespirationoccurringduring photosynthesis?Add back the O2thatwasconsumedbyplantrespirationtoobtainthe totalphotosyntheticrate.

Data Table 4: Comparison of Photosynthetic Rate

My Photosynthetic Rate Result

Average of Other Students’ Photosynthetic Rate

Results

N = 154 (number of data averaged)

156

153+152+156=461/3=153.667

Data Table 4: Observation of pH Change in the Oxygen Cycle

Contents of

Respirometer

Initial

Color

T0, minutes

Final

Color

T1, minutes

Total time for color change,

T1 – T0, minutes

Elodea,

Bromothymol blue

solution

Yellow/Green

15

Blue

50

35

Elodea, Bromothymol blue solution in foil

Yellow/Green

25

Greenish Blue

85

60

Data Table 5: Comparison of Photosynthetic Rate

My Result: Total time for color change,

T1 – T0, minutes

Average of Other Students’ Results: Total time for color change,

T1 – T0, minutes

N = 72 (number of data averaged)

Elodea, Bromothymol blue solution

35

50+60+40=150/3= 50

Elodea, Bromothymol blue solution in Foil

60

85+70+60=215/3= 71.667

Exercise1: ChlorophyllPigments

Results

Rf= distancetotopof pigmentin mm ÷ distancetotopof solventfront.

RfAverage= averageof other students’Rf values,if available.

1. Rfvaluesarecalculatedratiosofhowfaramoleculemovedupthepaperchromatographascomparedtothelengthofthesolventfront.Thesevaluesaretypicallyequivalentformultipletrials.CalculateyourRf valuesbased on yourpaper stripresults,and recordthem inTable1. The Rf valueof the solventfrontwill always= 1.0, since Rf is a ratio.

2. Constructa stackedbar graphtodemonstratehowthe Rf valueand the chlorophyllpigmentarerelated.They-axiswillrepresenttheRfscalefrom0.0to1.0.Onthebargraph,labelthecalculatedRf with the name of the associatedchlorophyllpigment.When complete,the bar graphshouldcloselyresembletheactualchromatograph.Includeastackedbargraphforyourresultsplusanotherstackedbar graphnexttoyourgraphwithyourclassmates’averagedvalues.

Questions:

A.Identifytheareasofpigmentsthatyouobserveonthefilterpaper.Aretheylocatedintheorderthatyouexpected?

Theyportray an observable location in the expected area.

Ifnot, whynot?

Theyare in the right position, and a deviation can only happen whereaccuracy is not observed.

B. Compareyourpaperstripresultstotheresultsoftheradicchiopaperstripsbelow.Arethesame pigmentspresentin radicchioleaves?

Theyare different.

Ifnot, which chlorophyllpigmentsaremissing?

ChlorophyllA and B which are green.

Howmightyouhaveguessed thatthis mightbe the case?

Radicchioleaves are pink or reddish whereas those of spinach are green. Due tothe differences in color this explains the difference in pigments.

Example of Results Obtained from Radicchio

Paper Chromatograph

Radicchio Paper Chromatograph, dried and marked in preparation for Chlorophyll Pigment Rf determinations

Discussion

A.Wasthe initialhypothesissupportedor refuted?Explain.

Therewas support of the hypothesis as a result of separation of bands.

B. Ifyoudo not see separatebands of coloron the filterpaper,whatmightyouconclude?

Theprobable conclusion is that the experiment failed and thus a properobservation should be conducted.

C. Whatmightexplainwhythe separationofthe colorsoccurred?

Themolecular composition is the reason behind the separation of colors.

D.Howdoyourvaluescomparetoyourclassmates’valuesforthesamepigmentsonTable1andin yourgraph?If theyarenot similar,whatmaybe the reason?

Theresults were similar and any deviation from the graphical results tothat of tables is an indication of inaccuracy in reading andtranslating the data.

Exercise2:ConversionofLightEnergytoFoodby

Plants

Questions

A.Whatmolecule wasproducedbythe Elodea while it wasexposedtolight?

Thepresence of light explains the presence of photosynthesis, thus thetwo molecules are Oxygen and glucose in form of energy.

B. Whichorganelle(s)in the plantcell is responsibleforthis reaction?

Photosynthesistakes place because of the presence of chlorophyll and the specificorganelles are chloroplasts.

C. Fromwherewasthis molecule derived?

Themolecule came from water

D.Whatwasthe purpose of the light?

Lightis used to facilitate the process of photosynthesis.

E. Whatmolecule wasproducedbythe Elodea while it waswrappedin aluminum foil? Carbondioxide and water

F. Whichorganellewasresponsibleforthis reaction?

Mitochondriais the organelle responsible.

G.SetupatablesimilartoDataTable3:ComparisonofPhotosyntheticRateintheLabReportAssistantsection.CompareyourRateofPhotosynthesistotheaverageratesreportedbyotherstudentsin Table3, if possible. How similar wasyourresulttotheirs?

Therate was slightly higher at 156 compared to a 154 for 3 otherclassmates.

H.Nameatleastthreeexperimentalvariablesthatcouldexplainwhyyouroutcomemightvaryfromthatof other studentsor fromyourown,if yourepeatedthe experiment.

Thevariation of temperature, tilting the angle of the test tube andaccuracy in measurements.

I. Howcouldone determinehowmuch oxygenis producedbythe plantin one hour?

Oxygenlevels produced were determined using the already given formula andaccuracy was a key factor.

1. Fromgeometry,recallthatVolume= πr2h,wherer = inside radiusof a circle,or herethe inside of the tube, and h = lengthof the movement,which means π x radiussquared

xheight.Since the radiusis ½ of the inside diameter,this equationisequivalentto

=3.1416 x (inside diameterof the benttube in mm ÷ 2)2xheight(equivalenttothe

distancethatthe solutiontraveled)= volumein mm3.

3.1416x(2.5mm/2)sq’d.X156=Ymm3

3.1416(1.25)sq’dX 156= Ymm3

3.1416×1.5625×156=Ymm3

765.765mm3

2. To convert mm3 volume to uL (typically the volume specification used atthis level of measurement), use the conversion factor of 1 mm3 = 1 uL.Dothecalculationtodeterminethevolumeofoxygenthatisproducedbytheplantinonehour.

765.765mm3=795.125uLthe ratio is 0.96:1

3. Howlong wouldthe plantneed tophotosynthesizetoproduceone literof O2?

31.5hrs

Discussion

A.Didthis experimentsupport or refuteyourinitialhypothesis.Explain.

Therewas a refute in the hypothesis. The prediction was wrong concerningthe rise in the level of the solution resulting from the pressurecaused by the presence of oxygen and carbon dioxide inside the tube.There was also a reduction in the predicted time of change in color.

B. Chlorophyllgivesplantleavestheir greencolor,(or red,in the caseof radicchio,since it lacksa pigmentthatis typicallypresentin greenleaves).Researchlightand color,and hypothesizewhetherchlorophyllabsorbsgreenlighttoanyappreciableextent.Proposeanexperimentsimilartothe one thatyoujustperformedthatcouldbe used tosupport yourhypothesis.

Thereis notable change of the color of plants leaves, this is caused bythe absorption of light and it is transmitted through the leaves. Totest the above scenario one is supposed to use colored bulbs in theexperiment. Observational photosynthesis data will be varied from thedifferent scenarios.

C. Thereis currentcontroversyas towhetherthe atmosphereis warmingdue tothe burningoffossilfuelsandthedestructionoftherainforests(theGreenhouseEffect).Howdoesphotosynthesisand respirationrelatetothis controversy?

Thetwo processes are affected by the global warming effects. There isrise in temperature which affects the process of respiration.

D.Whyarethe tropicsparticularlyimportanttooxygenproduction?

Theyhave higher coverage of vegetation and the temperatures are veryconducive for the growth of various plants. There is annual exchangeof carbon dioxide and oxygen in these tropical places.

Presenceof many trees acts a source of cooling effect especially because theyboost the rainfall levels in those tropical areas.

Forestcover provides an avenue for lowering the effects of global warmingand this supports the survival of other species on the plant. Whenthe forest cover are less interfered with, they have the capacity toreplenish themselves and thus purify the air which is inhaled byanimals and human beings.

Therefore,whyshould yousupport actionsthatreducethe cuttingofrainforests?

Forestcoverage provide proper avenues for the purification of air. Plantstake in carbon dioxide and releases oxygen that is inhaled by humanbeings. Cutting down trees will result to accumulation of carbondioxide in the atmosphere which will in turn result into globalwarming.

Forestcover provide an avenue for lowering the effects of global warming,and this supports the survival of other species on the plant. Whenthe forest cover are less interfered with, they have the capacity toreplenish themselves and thus purify the air which is inhaled byanimals and human beings.

Forestalso supports the survival of water catchment areas. When forestsare not interfered with, they support sources of rivers which supportboth animal and human life on the planet. There is also arelationship between a large forest cover and the amount of rainfallreceived in an area.

Forestcover adds to the biodiversity of the planet earth. Through theprocess of photosynthesis, life is supported on earth. Plants consumecarbon dioxide, thus cleaning the atmosphere and release oxygen whichis vital for the survival of animals and human beings. This explainsthe interrelationship of the various elements of the ecosystem.

E. Whilethisexercisehasaddressedoxygenproduction,whatotherimportantproductsresultfromphotosynthesis?Hint:Besidetheproductionofoxygen,whyareallanimalsdependentonplants?

Thereis an inter relationship between animals and plants. Animals dependon plants as the sole source of food and energy. Plants, on theother hand, produce oxygen which is vital for animals. Plants aresources of life to animals. This is so because, animals depend on themany minerals found in plants for their survival. There is a mutualrelationship between the two elements that is plants and animals.This is depicted by the fact that, animals provide manure that acts asource of minerals for the survival of plants, while at the same timethose animals rely on the plants for their survival.

Exercise3: RespirationinPlants

Questions

  1. Why is the Elodea rinsed in distilled water?

Itis used to facilitate the process of photosynthesis as well rinsingthe leaf. The process also entails cleaning the test tube andavoiding instances of contamination. Distilled water has a PH levelof 7 and thus it does not affect the PH of the leaf during theexperiment.

  1. What gas did you add to the Bromothymol blue solution?

Thegases added is Carbon Dioxide (CO2)

Howdo youknow?Respirationisour primaryformof energyproduction.

Humanbeing breathe in oxygen and breath out carbon dioxide.

C. Whydid the colorturn moregreen-yellowor yellowwhen youbreathedintoit?

Thepresence of oxygen gas lower the PH level while Carbon Dioxide raisethe PH levels

D.Writean equationforthe reactionthatexplainsthe colorchange.

6CO2+ 6H2O+ Energy –&gt C6H12O6+ 6O2

Breath=B

Brom.Blue= T

Color=Z

B+T=Z

E. WhatcolorchangeoccurredafteryouplacedtheElodeainthetesttubeandturnedthelightsourceon/off?

Therewas an alternate color change from yellow green to green blue

F. Whatgasis producedand responsibleforthis change?

Oxygengas is the one produced and it raises the PH levels. Presence ofoxygen makes the alkaline levels of the solution to go up. Thesolution becomes basic.

G.Whatgasis being removed?

Thegas removed is carbon dioxide

H.Whatprocessis occurring in the firsttrialwithout the aluminum foil?

Theinitial process is photosynthesis

I. Whatdidyouobservewhenyourepeatedtheexercisewiththetesttubecontainingthe

Elodeawrappedin aluminum foil?

Cellularrespiration

J. Whatgasis produced?

CarbonDioxide is released during respiration

Whattermcouldbe applied tothe secondtrial?

Cellularrespiration is the process that takes place

K. Whichprocesstooklonger?

Cellularrespiration takes longer than photosynthesis

Why?

Thisis attributed to the chemical requirement of the process. Cellularrespiration involves uptake of energy for the process to occur, thisis so because even at no lighting system, the process would stilltake place.

Discussion

A.HowdidthetimeforcolorchangevarybetweenwhentheElodeawaspresentinthetesttube

(trial1) versuswhen the Elodea waswrappedin aluminum foil?Whatmightexplainthis?

Thetiming difference between 25 and 30 minutes

B. Whydo both plantsand animals respire?

Respirationtakes place even in the absence of light as compared tophotosynthesis which takes place only in the presence of light.

Respirationprocess entails intake of oxygen to facilitate the oxidation processwhich is an energy consuming activity. The end result of this processis the production of food which support both animals and human life.

Wouldlifein either groupbe possible without respiration?

Lifecan only be possible in the absence of respiration if and only ifthere is a proper supply of light.

C. Wasthe initialhypothesissupportedor refuted?Explain.

Theoccurrence of both respiration and photosynthesis processes supportthe hypothesis

D.HeatingcausesaBromothymolblueindicatorsolutiontochangefromyellowtoblueveryrapidlywithout a plantpresent.Whatexplainsthis reaction?

Theprocess takes place because of removal of oxygen which when it coolsdown regains its normality.

Howdidyoucontrolforheatin this exercise?

Heatingwas controlled through the use of 150 watt bulb and also placing ajar of water in between the bulb and the tube

E. SetupadatatablesimilartoDataTable5:ComparisonofPhotosyntheticRateintheLab

ReportAssistantsection.Compareyourresultstothoseofyourclassmates,ifavailable,inTable

5.Wereyourresultssimilar? Whattrendsdo youobservebetweenthe twotrials?

Respirationprocess rate is the similar with a slight varying in time.

F. Explainwhyyourdatamayhavedifferedfromthatofotherstudents.Whatvariablescouldexplainthis difference?

Thedifferences in temperatures and also the general condition of theplant used.

Alterationof temperatures interfere with the minimum requirements for theexperiment to be performed and produce relevant results. This willcause a variation in the results among the various groups performingthe experiment.

G.HowwouldyoubeabletochecktoensurethatitwastheElodeaplantthatfacilitatedthecolorchangeand not some other factor?

Tryand remove the plant and make the observation.

H.Howdoplants,suchasPinedrops,Pterosporaandromedea,ortheGhostPlant,Monotropauniflora,thatarenot photosynthetic,maketheir food?

Theyapply the process of cellular respiration for survival. They alsoapply the parasitic form of relationship with their hosts

Theplants apply the concept of attaching themselves to the host plant.This becomes a source of food and survival. Photosynthesis only takesplace in the presence of chloroplast organelles and these plants donot contain the element. Therefore, for their survival they have tosolely rely on other plants.

Dotheyrespire?

Yes,they have cellularrespiration

Respirationprocess does not require the presence of chloroplast to take place asit is the case with photosynthesis.

LaboratorySummary

Whathaveyoulearned fromdoing this laboratory?

Oneof the key lessons learnt from the experiment is patience as theentire process requires devotion of time. All the three experimentsserved the same function of showing the process of photosynthesis andrespiration. Another crucial lesson learnt from the experiment isdiscipline in observation of the events as they happen and as onerecords the. Data analysis and presentation is another key lessonlearnt from the experiments. There is also the lesson of theimportance of the collaboration process among the various groupsconducting the experiment this promotes team work. There is also thestudy of the importance of conserving forest cover as stated in thefollowing points:

Forestcoverage provides proper avenues for the purification of air. Plantstake in carbon dioxide and releases oxygen that is inhaled by humanbeings. Cutting down trees will result to accumulation of carbondioxide in the atmosphere which will in turn result into globalwarming.

Forestcover provide an avenue for lowering the effects of global warming,and this supports the survival of other species on the plant. Whenthe forest cover is less interfered with, they have the capacity toreplenish themselves and thus purify the air which is inhaled byanimals and human beings. Forest also supports the survival of watercatchment areas. When forests are not interfered with, they supportsources of rivers which support both animal and human life on theplanet. There is also a relationship between a large forest cover andthe amount of rainfall received in the area.

Forestcover adds to the biodiversity of the planet earth. Through theprocess of photosynthesis, life is supported on earth. Plants consumecarbon dioxide, thus cleaning the atmosphere and release oxygen whichis vital for the survival of animals and human beings. This explainsthe interrelationship of the various elements of the ecosystem.

Workscited

Hopkins,William G. Photosynthesisand Respiration.New York: Infobase Pub, 2006. Internet resource.

Kê,Bacon. Photosynthesis:Photobiochemistry and Photobiophysics.Dordrecht [u.a.: Kluwer Academic, 2001. Print.

Lambers,H, and Miquel Ribas-Carbo. PlantRespiration: From Cell to Ecosystem.Dordrecht: Springer, 2005. Internet resource.

Wada,Hajime, and Norio Murata. Lipidsin Photosynthesis: Essential and Regulatory Functions. Dordrecht, The Netherlands: Springer, 2009. Print.

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