EXERCISE 12 PHOTOSYNTHESIS A,B & C

EXERCISE 12 PHOTOSYNTHESIS A,B & C ||| Glasses Group |||Lea Conda | Hanna Estadilla | Fretzie Masaoy | Lorena Osorio INTRODUCTIONWHAT IS PHOTOSYNTHESIS?It is the biological process that includes the capture of light energy and its transformation into chemical energy of organic molecules, which are manufactured from carbon dioxide and water. (Berg, 2012)In photosynthesis, plants convert light energy to chemical energy stored in carbohydrate molecules.Fig. 1.1 Photosynthesis Equation

TWO STAGES OF PHOTOSYNTHESIS REACTIONSLight-dependent reactionsCarbon fixation reactions / Calvin CycleLIGHT-DEPENDENT REACTIONSPHOTOSYSTEMS I and II

PS1: P700PS2: P680Fig. 1.2 Photosystems TWO TYPES OF ELECTRON TRANSPORTNoncyclic Electron Transport H2O PSII PSI NADP+Cyclic Electron Transport

CALVIN CYCLEThree Stages/ Steps CO2 uptakeCarbon ReductionRuBP Regeneration

Fig. 1.3 Calvin CycleOBJECTIVESTo determine the role of chlorophyll in photosynthesis.To determine the role of light in photosynthesis.To determine the role of carbon dioxide in photosynthesis.

ROLE OF CHLOROPHYLL IN PHOTOSYNTHESISMaterialsA. The Role of Chlorophyll in PhotosynthesisVariegated leaf95% ethyl alcoholTap water or distilled waterTest tubeIKI solutionBeaker (1000 ml)StovedropperMethod / ProcedureMethod / Procedure

Fig. 2.1 Mayana leaf

Fig. 2.2 Boiling of Mayana leaf Method / Procedure

Fig. 2.3 Extraction of pigments

Fig. 2.4 Bleached leaf with IKIResults & Discussions

GROUP NAMERESULTGlasses GroupPresence of StarchGroup 1Presence of StarchNameless GroupPresence of StarchFaura GroupPresence of StarchChlorophyll GroupPresence of StarchTable 3.1 Role of Chlorophyll Experiment ResultsConclusionThe essential elements of photosynthesis are CO2 from the atmosphere, H2O from the soil and light energy. With these primary elements, the plant is capable of producing its own food along with the by-product of oxygen which is beneficial to man.

ConclusionIn the leaf, excess glucose is rapidly converted to starch, so we test leaves for starch to show that photosynthesis has happened.Putting a drop of IKI solution is a way to determine the presence of starch in leaf. Dark blue is the positive color reaction for the presence of starch. The variegated leaf exhibited positive color reaction for the presence of starch in the green part of the leaf.

ConclusionThe starch grains were located at the green parts of the leaf where chloroplasts are present.There were little to none starch grains on the white parts of the leaf. In order for the leaf to undergo photosynthesis and produce food in the form of starch, chlorophyll is needed. ROLE OF LIGHT IN PHOTOSYNTHESISMaterialsB. The Role of Light in PhotosynthesisPotted plantCarbon or black paperPaper clipIKI solution95% ethyl alcoholTap water or distilled waterBeaker(1000 ml)Test tubeStoveMethod / ProcedureMethod / Procedure

Fig. 2.5 Angels Breath leaf

Fig. 2.6 Extraction of pigmentsMethod / Procedure

Fig. 2.7 Leaf without IKI

Fig. 2.8 Bleached leaf with IKIResults & Discussions

GROUP NAMERESULTGlasses GroupNo Presence of StarchGroup 1No Presence of StarchNameless GroupNo Presence of StarchFaura GroupNo Presence of StarchChlorophyll GroupNo Presence of StarchTable 3.2 Role of Light Experiment ResultsConclusionA leaf of the plant, placed in the dark for 2 days, when tested with IKI solution showed no change in color which means that starch is not present.The purpose of putting the plant in the dark for 48 hours is to eliminate light and consume all products of photosynthesis before the conduction of the experiments.ConclusionTherefore, sunlight is needed for photosynthesis to occur. It gives the energy for the mechanism to start. ROLE OF CARBON DIOXIDE IN PHOTOSYNTHESISMaterialsC. The Role of CO2 in Photosynthesis3 test tubesMarkerPhenol redDropperHydrilla sprigsNaHCO3Distilled or tap waterMethod / ProcedureMethod / ProcedureMethod / Procedure

Fig. 2.9 Test Tube A

Fig. 2.10 Test Tube BMethod / Procedure

Fig. 2.11 Test Tube C

Fig. 2.12 A, B and CResults & Discussions

GROUP NAMEA B CGlasses GroupRed-OrangeNo BubblesDark RedBubblesOrangeNo BubblesGroup 1Dark Red Orange -Nameless GroupYellow-OrangeNo bubblesDark PinkBubblesPinkNo BubblesFaura Group---Chlorophyll GroupYellowNo BubblesDark BubblesPinkNo BubblesTable 3.3 Role of CO2 Experiment ResultsConclusionThe distilled water should be boiled first to remove all impurities / dissolved gases that contaminates the water, reducing it to its purest form.The Hydrilla was inverted because the gas produced exits at its cut portion.Tiny bubbles were formed in test tubes B and C due to the reaction of NaHCO3 with water creating an unstable acid that easily decomposes into H2O is CO2.ConclusionTest tube A showed minimal or no bubble formation at all since distilled water used was boiled. The Hydrilla in B had a continuous bubble formation emanating from the cut portion of the plant. CO2 bubbles get caught at the surface of the plant. ConclusionPHENOL RED turns: a) Yellow acidic; pH below 6.8 b) Orange neutral; pH 7 c) Pink basic; pH above 8.2ConclusionTEST TUBE A: When dropped with Phenol Red, the solution resulted into an orange color, indicating that there is no significant change in pH of the set-up.TEST TUBE B & C: When dropped with Phenol Red solution resulted into a red color meaning solutions in test tubes B & C becomes basic.ConclusionTEST TUBE B is more basic compared to C since the Hydrilla absorbs some of the naturally escaping CO2, speeding up the reduction of CO2 in the test tube, leaving more hydroxide ions.TEST TUBE C is basic since most of the carbonic acid already decomposed into H2O and CO2 and the molecules of CO2 have already dispersed from the rest of the tube.Plants absorb CO2 since it is needed for the production of plants food.ConclusionSIR OBICOS CORRECTIONS/ADDITIONAL INFORMATION:NaHCO3 is used to introduce CO2 into the distilled water which was previously to remove gases. It separates into Hydroxide ions and CO2.Test Tube C must turn Yellow since CO2 is present because of the NaHCO3. The result obtained by the groups (pink in color) must be because other gases / impurities have entered the solution.

CONCLUSIONPHOTOSYNTHESIS

Fig. 5.1 Photosynthesis EquationREFERENCEINTERNET SOURCEShttp://www.elateafrica.orghttp://www.nuffieldfoundation.org

PREVIOUS REPORTS / LECTURESHannas buddy 2nd Year BS Biology Carl SalazarDr. Rosario Rubites Lectures on Photosynthesis

BOOKSIntroduction to Plant Biology 4th Edition by James MausethIntroduction to Botany by Linda R. BergBiology by CampbellPlant Systematics by Michael G. Simpson