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
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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
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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
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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 10OC – 30OC• Above 40OC enzymes may
become denatured
Influence of some factors on the rate of photosynthesis
![Page 4: Photosynthesis and the Environment 6 CO 2 (g) + 6 H 2 O (l) [CH 2 O] + 6 O 2(g) Net CO 2 uptake= photosynthetic CO 2 uptake – photorespiratory CO 2 evolution](https://reader036.vdocuments.mx/reader036/viewer/2022062905/5a4d1acd7f8b9ab0599702cf/html5/thumbnails/4.jpg)
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
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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
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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
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Cheaper New More Effective Solar Cells Imitate Photosynthesis - They employ synthetic pigments imitating the natural ones - Softpedia