Unit 3

Question 1

Photosynthesis

Answer 1

Two stage process

Question 2

First stage of photosynthesis

Answer 2

Called the light reactions

Question 3

During the light reactions

Answer 3

Light energy from the sun is trapped by chlorophyll in the chloroplasts and is converted into chemical energy which is used to generate ATP.
Water is split to produce hydrogen and oxygen.
Oxygen diffuses from the cell.

Question 4

Second stage

Answer 4

Called carbon fixation.

Question 5

What is carbon fixation

Answer 5

Series of enzyme controlled reactions

Question 6

During carbon fixation

Answer 6

Hydrogen and ATP with carbon dioxide are used to produce sugar

Question 7

Process of photosynthesis

Answer 7

Light energy

Carbon dioxide + water —————-> glucose and oxygen

Question 8

What is the chemical energy in sugar available for

Answer 8

Respiration or the sugar can be converted into other substances, such as starch and cellulose.

Question 9

What are the limiting factors of photosynthesis

Answer 9

Carbon dioxide concentration, light intensity and temperature

Question 10

What happens if the limiting factors of photosynthesis are in short supply

Answer 10

The rate of photosynthesis will slow down and so too will plant growth