Leaf adaptations for photosynthesisAdaptations to optimise
photosynthesisLeaf mosaicLeaves of a plant grow and space out so
that they shade one another as little as possible
Phototropismdetects the direction of sunlight and grows in its
direction, making sure that all its leaves get maximum sunlight
Leaf mosaic
MECHANISM OF PHOTOSYNTHESIS
Mechanism of photosynthesisPhotosynthesis:Takes place in place
leaves within the chloroplasts2 stages process:Stage 1: the light
reactionStage 2: the dark reaction
Light reactionTakes place in the presence of sunlight &
chlorophyllChlorophyll absorb sunlight becomes activated & this
energy is used to:Produce energy in the form of ATP for use in dark
reactionSplit up the H2O molecules (photolysis) into Hydrogen &
Oxygen
Dark ReactionTakes place without the presence of sunlightATP
& Hydrogen : used to reduce CO2 to glucoseTo form 1 molecule of
glucose:12 molecules of H2O produce : 6 O2 & 24 H24 H reduce 6
molecules of CO2 to form 1 glucose + 6 H2O
General equation
Similarities between light reaction & dark reactionBoth
process are catalysed by enzymesBoth takes place in
chloroplastDifferencesLight reactionAspectDark reactionIs a
photolysis reaction using light energyType of reactionIs a series
of biochemical reaction which does not require lightH2O &
sunlightInput of raw materialCO2 & chemical energyO2 released
& H goes into dark reactionProduct outputCarbohydrate/glucose
& H2OIn the granum membraneLocation of processIn the
stromaYesAbsorption of lightNoOnly in the presence of lightWhen
does it happen?Only after the light reaction completeForms
ATPEnergyUses ATP
FACTORS AFFECTING PHOTOSYNTHESIS
3 main factors affecting the rate of photosynthesis are:Light
intensityCO2 concentrationTemperature
Limiting factor : any factor affecting the rate of metabolic
reactionLight intensity, CO2 concentration & temperature can be
a limiting factor depending on which one is short in supply
Effect of light intensity
Effect of carbon dioxide
Effect of CO2 concentration
Effect of temperature
Effect of temperature
To study the effect of light intensity on the rate of
photosynthesis
