ST3. Photosynthesis N5 (LOE)

Question 1

What is photosynthesis?

Answer 1

Photosynthesis is the process in which green plants convert light energy into chemical energy in the form of glucose

Question 2

What are the 2 stages of photosynthesis?

Answer 2

Light reaction and carbon fixation

Question 3

What happens during light reaction?

Answer 3

• Light energy from the sun is trapped by the chlorophyll in the chloroplasts
• This energy 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

What happens during carbon fixation?

Answer 4

• Hydrogen and ATP with carbon dioxide are used to produce sugar

Question 5

What is carbon fixation?

Answer 5

A series of enzyme controlled reactions

Question 6

What’s the word equation for photosynthesis?

Answer 6

……………………………………….light energy……………………………………….
carbon dioxide + water ———————–> sugar + oxygen

Question 7

What is the chemical energy in sugar available for?

Answer 7

Respiration

Question 8

What else can the sugar (produced in photosynthesis) be used for?

Answer 8

The sugar can be converted into other substances, such as starch (storage) and cellulose (structural)

Question 9

What are the limiting factors of photosynthesis?

Answer 9

Carbon dioxide concentration, light intensity and temperature

Question 10

What happens if any limiting factors are in low supply or are absent?

Answer 10

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

Question 11

How can you investigate the limiting factors of photosynthesis?

Answer 11

The rate of photosynthesis can be investigated and results can be plotted onto a graph to allow analysis