Photosynthesis
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Transcript of Photosynthesis
PhotosynthesisPhotosynthesis
Stages of PhotosynthesisStages of Photosynthesis
TEKSTEKS
9B Compare the transfer of energy from 9B Compare the transfer of energy from one type of molecule to the next in one type of molecule to the next in respiration and photosynthesisrespiration and photosynthesis
ChloroplastsChloroplasts
Thylakoid membraneThylakoid membrane GranaGrana StromaStroma
Two StagesTwo Stages
Light Dependent ReactionsLight Dependent Reactions Convert sunlight to ATP energyConvert sunlight to ATP energy Occurs on thylakoid membraneOccurs on thylakoid membrane
Light Independent ReactionsLight Independent Reactions Uses ATP to make glucoseUses ATP to make glucose Occurs in stromaOccurs in stroma
Light Dependent Light Dependent ReactionsReactions
Photochemical ReactionsPhotochemical Reactions Non-cyclic Electron FlowNon-cyclic Electron Flow ChemiosmosisChemiosmosis
Light Dependent Light Dependent ReactionsReactions
Photochemical ReactionsPhotochemical Reactions Light energy knocks Light energy knocks
electron off chorophyll in electron off chorophyll in photosystems I and IIphotosystems I and II
Light Dependent ReactionsLight Dependent ReactionsNon-cyclic Electron FlowNon-cyclic Electron Flow
11stst stage stage photosystem I passes 2 electrons to NADPphotosystem I passes 2 electrons to NADP++
Photo I now short 2 electronsPhoto I now short 2 electrons
22ndnd stage stage Photosystem II passes 2 electrons to ETC in Photosystem II passes 2 electrons to ETC in
thylakoid membranethylakoid membrane H protons pumped across membraneH protons pumped across membrane Electrons given to Photo I at end of ETCElectrons given to Photo I at end of ETC Now Photo II short 2 electronsNow Photo II short 2 electrons
Light Dependent Light Dependent ReactionsReactions
Non-cyclic Electron Flow, cont..Non-cyclic Electron Flow, cont..33rdrd stage-photolysis stage-photolysis 2 electrons to photo II2 electrons to photo II 2 H protons pumped to inside of grana2 H protons pumped to inside of grana Oxygen leaves plant as wasteOxygen leaves plant as waste
Net effect: Net effect: NADPH + H producedNADPH + H produced HH+ + added to granaadded to granaOxygen released as wasteOxygen released as waste
Light Dependent Light Dependent ReactionsReactions
ChemiosmosisChemiosmosis HH++ flows back through membrane via ATP flows back through membrane via ATP
synthetasesynthetase ATP producedATP produced
Light Dependent Light Dependent ReactionsReactions
Products:Products: OxygenOxygen NADPH + HNADPH + H ATPATP
LDR
Light Independent Light Independent ReactionsReactions COCO22 + H + H++ + ATP used to make glucose + ATP used to make glucose
LIR
Factors Affecting Factors Affecting PhotosynthesisPhotosynthesis
TEKSTEKS
9B Compare the transfer of energy from 9B Compare the transfer of energy from one type of molecule to the next in one type of molecule to the next in respiration and photosynthesisrespiration and photosynthesis
Light IntensityLight Intensity
What effect does What effect does it have?it have? Rate increases Rate increases
then levels offthen levels off
Why?Why? More reactants More reactants
than enzymes… than enzymes… can’t keep upcan’t keep up
TemperatureTemperature
What effect does it What effect does it have?have? Increases then Increases then
decreasesdecreases Why?Why?
Molecules move Molecules move faster; therefore, more faster; therefore, more reactionsreactions
Enzymes denature at Enzymes denature at high temperatureshigh temperatures
Carbon DioxideCarbon Dioxide
What effect does it What effect does it have?have? Low conc. - slowsLow conc. - slows High conc. - slowsHigh conc. - slows
Why?Why? Low amounts of Low amounts of
reactants slow ratereactants slow rate
WaterWater
What effect does it have?What effect does it have? Little water slows rateLittle water slows rate
Why?Why? Stomata closeStomata close
OxygenOxygen
What effect does it have?What effect does it have? Slows rateSlows rate
Why?Why? Destroys pigmentsDestroys pigments PhotorespirationPhotorespiration
CAMCAM
Used by desert plantsUsed by desert plants Close stomata during dayClose stomata during day COCO22 gathered at night and stored gathered at night and stored
Rate of photosynthesis is lowRate of photosynthesis is low