PLANT PHYSIOLOGY
PHOTOSYNTHESIS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
there is not enough CO2 to fuel the reaction
|
|
|
there is not enough light to power the reaction
|
|
|
the shape of enzymes involved in the reaction denature
|
|
|
the mitochondria cannot function at these temperatures
|
|
|
all of the above could explain why the rate drops off
|
Detailed explanation-1: -Photosynthesis is an enzyme specific process. All enzymes act at an optimum temperature (i. e., 25−35∘C). if temperature increases, enzyme gets denatured, thus leading to a fall in the rate of photosynthesis.
Detailed explanation-2: -Because it is an enzyme-controlled process, this is the case. It occurs as a result of enzymes being involved in temperature-sensitive chemical processes. At lower temperatures, the number of molecular collisions between the substrate and the enzymes limits the pace of photosynthesis.
Detailed explanation-3: -Excess water loss (transpiration) causes stomata closure and therefore decreases the photosynthetic rate.
Detailed explanation-4: -At high intensities, the temperature of the plant increases which leads to increased transpiration in the plant. This leads to the closing of the stomata which leads to a reduced CO2 intake. Thus, leading to a reduction and finally stoppage of photosynthesis. Therefore, excessive light inhibits photosynthesis.