3.3 Photosynthesis

Question 1

Describe the first stage photosynthesis occurs in chloroplasts:

Answer 1

Step 1: Light-dependent reactions

• Requires light to occur
• Light energy absorbed by chlorophyll is used to photolyase (break) water molecules into H+ ions and oxygen gas
• Occur in grama

Question 2

What is the formula for the first stage of photosynthesis occurring in chloroplasts?

Answer 2

Water → (light energy and chlorophyll) Hydrogen ions + Oxygen + ATP

Question 3

Describe the second stage photosynthesis occurs in chloroplasts:

Answer 3

Step 2: Light-independent reactions

• Occurs in the stromata
• Does not need light
• Hydrogen and ATP from the first stage, plus CO2 are used to make glucose and water

Question 4

What is the formula for the second stage of photosynthesis occurring in chloroplasts?

Answer 4

Hydrogen + ATP (charged battery) + Carbon Dioxide → Glucose + water + ADP (uncharged batter)

Question 5

Describe the 3 factors which affect the rate of photosynthesis:

Answer 5

• Light: As light increases, the rate will increase
• Carbon dioxide concentration: As CO2 increases, the rate will increase
• Temperature: As temperature increases, rate increases