Limiting Factors of Photosynthesis

Question 1

What are the 3 limiting factors of photosynthesis?

Answer 1

light intensity
co2 concentration
temperature

Question 2

How does light intensity affect photosynthesis?

Answer 2

the higher the light intensity the more energy there is for the L.D.R. so the faster the rate of photosynthesis

light needs to be the right wavelength - so they look green as they reflect green light and absorb blue and red

to increase rate of photosynthesis - use lighting at night, and greenhouse allows light to pass in

Question 3

How does co2 concentration affect photosynthesis?

Answer 3

co2 is the limiting factor - day time
co2 is about 0.04% of atmosphere
optimum co2 concentration = 0.4%
above 0.4% co2 has a negative effect on rate of photosynthesis

to increase rate of photosynthesis, burn fossil fuel in greenhouse to increase co2 concentration e.g. propane

Question 4

How does temperature affect photosynthesis?

Answer 4

photosynthesis is controlled by enzymes

if you increase the temp. you increase the rate of reaction up to the optimum temp.

beyond the optimum temp. the rate decreases

high temp causes stomata to close and this decreases co2 therefore decreases calvin cycle

burner increases temperature