CB6b Factors that affect photosynthesis

Question 1

What factors affect the rate of photosynthesis

Answer 1

• Temperature
• Light intensity
• Carbon dioxide concentration

Question 2

What is a limiting factor

Answer 2

A variable that limits the rate of a particular reaction

Question 3

Explain how the temperature affects the rate of photosynthesis

Answer 3

Higher temperatures provide more KE for enzymes involved in photosynthesis so the rate increases as temperature rises

The optimum temp is usually 25 degrees

if the temperature becomes too high enzymes become denatured and the rate of photosynthesis decreases

Question 4

Explain how light intensity affects the rate of photosynthesis

Answer 4

The rate of photosynthesis is directly proportional to light intensity therefore as light intensity increases the rate of photosynthesis increases

Question 5

Why does the rate of photosynthesis eventually plateau even if the light intensity continues to increase

Answer 5

Another factor (temp or co2 concentration) becomes limiting

Question 6

How can the effect of light intensity on the rate of photosynthesis be measured in the lab (2)

Answer 6

Using a light meter
Using the inverse square law

Light intensity new = og light intensity x distance™2

Question 6

How can the effect of light intensity on the rate of photosynthesis be measured in the lab (2)

Answer 6

Using a light meter
Using the inverse square law

Light intensity new = og light intensity x og distance™2
——————————————-
distance™2 new

Question 7

Why does the rate of photosynthesis decrease as the distance from a light source increases

Answer 7

Light intensity is inversely proportional to the square of the distance from the light source.
Thus as the distance increases light intensity decreases and the rate of photosynthesis decreases

Question 8

Explain how carbon dioxide concentration affects the rate of photosynthesis

Answer 8

As carbon dioxide concentration increases the rate of photosynthesis increases