Factors Affecting Photosynthesis

Question 1

Light intensity and wavelength

Answer 1

Too little slows down the rate of the light dependent stage

Question 2

Temperature and pH

Answer 2

Affects rate of enzymes on catalysing reactions

Question 3

Number of chloroplasts

Answer 3

Too few would slow down light dependent stage

Question 4

CO2 and water supply

Answer 4

They are both reactants needed for the process

Question 5

How temperature affects photosynthesis

Answer 5

Too low= the enzymes are too slow to be of an effect

Optimum = 25-30 degrees

Rate falls again at 40 degrees due to the enzymes denaturing

Question 6

What stage of photosynthesis does temperature effect?

Answer 6

Mainly the light independent stage but also the light dependent and proteins are also present

Question 7

The overall effect of carbon dioxide on the Calvin cycle

Answer 7

Optimum at 0.1%
CO2 is acidic so damages the leaves between 0.1 and 0.5%
>0.5% = another factor becomes limiting

Question 8

The overall effect of light intensity on the Calvin cycle

Answer 8

No light= no photosynthesis/ Calvin cycle

Increases until chlorophyll becomes saturated with light

Too high= damaging to some plants

Levels off when another factor becomes limiting

Question 9

Light intensity on Calvin cycle

Answer 9

Bright light= lots of ATP/NADPH so lots of conversion of GP to TP and RuBP

Dim light= not enough ATP or NADPH for the cycle to continue from GP to TP

Question 10

Carbon dioxide levels on the Calvin cycle

Answer 10

Hight concentration= lots of CO2 so rapid conversion of RuBP to GP and TP

Low concentration= too little CO2 to convert RuBP to GP and TP so more RuBP present