photosynthesis and the environment 6 co 2 (g) + 6 h 2 o (l) [ch 2 o] + 6 o 2(g) net co 2 uptake=...
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Temperature and the Rate of Photosynthesis The light reactions are not affected by temperature Calvin cycle is affected because of enzymes Optimal temperature is between 10 O C – 30 O C Above 40 O C enzymes may become denatured Influence of some factors on the rate of photosynthesisTRANSCRIPT
Photosynthesis and the Environment
6 CO2 (g) + 6 H2O(l) [CH2O] + 6 O2(g)
Net CO2 uptake= photosynthetic CO2 uptake – photorespiratory CO2 evolution – respiratory CO2 evolution
Net O2 evolution = photosynthetic O2 evolution – photorespiratory O2 uptake – respiratory O2 uptake
Light Intensity and the Rate of Photosynthesis
• Irradiance – light intensity per unit area of leaf• Light response curve shows the effect of increasing
irradiance on the rate of photosynthesis
• Light-compensation point - CO2 uptake equals CO2 evolution • Light-saturation point – occurs at the irradiance
level at which the carbon fixation reactions reach a maximum overall rate
Temperature and the Rate of
Photosynthesis• The light reactions are not
affected by temperature• Calvin cycle is affected
because of enzymes• Optimal temperature is
between 10OC – 30OC• Above 40OC enzymes may
become denatured
Influence of some factors on the rate of photosynthesis
Oxygen Concentration and the Rate of Photosynthesis
• High oxygen levels have an inhibitory effect on photosynthesis
• Competition between O2 and CO2 for the active sites on rubisco
Photosynthetic Efficiency• Quantum yield: net CO2 uptake per unit of light energy
(photons) absorbed• C3 plants are more efficient at lower temperatures and
C4 plants are more efficient at higher temperatures
Sun Plants vs. Shade Plants• Shade plants have thinner, broader and greener leaves• Shade plants more efficient at harvesting light at low
intensities
• Sun plants have a higher light-compensation point• Sun plants have a higher light-saturation point
Cheaper New More Effective Solar Cells Imitate Photosynthesis - They employ synthetic pigments imitating the natural ones - Softpedia