5.6.6 Using the products of the light-dependent reaction

Question 1

What happens during the light-dependent stage of photosynthesis?

Answer 1

1. Reduced NADP is produced when hydrogen ions combine with the carrier molecule NADP using electrons from the photolysis of water
2. ATP is produced from ADP and Pi by ATP synthase in a process called photophosphorylation
3. Photophosphorylation uses the proton gradient generated by the photolysis of water
4. Energy from ATP and hydrogen from reduced NADP are passed from the light-dependent stage to the light-independent stage of photosynthesis

Question 2

What are the energy and hydrogen used for during the LIR?

Answer 2

To produe complex organic molcules, including carbohydrates such as:
- Starch (for storage)
- Sucrose (translocation around the plant)
- Cellulose (making cell walls)