Component 1.2 - Light IS

Question 1

Describe the process of the Calvin cycle

Answer 1

1) Ribulose biphosphate (RuBP) combines with CO2 (CO2 fixation) glycerate-3-phosphate (GP) catalysed by enzyme rubisco
2) GP is reduced to triose phosphate by reduced NADP (NADPH -> NADP) and energy is provided by ATP made in LDS
3) Most of the triose phosphate is converted into ribulose phosphate (5C) which regenerates RuBP and this requires ATP

Question 2

What can be synthesised from the triose phosphate in the Calvin cycle?

Answer 2

1) Glucose (fructose biphosphate)
2) Lipids
3) Amino acids with addition of nitrogen from nitrates

Question 3

Where does the Calvin cycle take place?

Answer 3

Stroma

Question 4

What could the hexose sugars be used for?

Answer 4

Cellulose, proteins, energy source

Question 5

Why are cycles performed in organelles?

Answer 5

1) Reactions occur in isolation and small volumes
2) Keep products separate from cytoplasm by membranes
3) Can use mitochondria close to areas needing ATP