Affected by :
Concentration of carbon dioxide
Both the concentration of carbon dioxide & temperature stop the rate of reaction from
increasing further along PQ.
The rate of photosynthesis will not increase although the light intensity is increases.
When CO2 concentration is raised to 0.13%, the rate of photosynthesis is higher. (graph II)
At very high light intensity, the rate of photosynthesis slows down because the chlorophyll
pigment is damaged by UV rays.
If there is no other limiting factors that limit the photosynthesis process, as the
concentration of carbon dioxide increases, the rate of photosynthesis increases.
Although the concentration of carbon dioxide keeps increasing, the rate of photosynthesis
will not increase further because light intensity acts as limiting factor.
An increase in 100C in the surrounding temperature will decrease the rate of photosynthesis
The optimum temperature of varies for each species.
But most plants : between 250C to 300.
If temperature is too high, photosynthetic enzymes are destroyed by denaturation.