CIE A Level Biology复习笔记13.1.2 Stages of Photosynthesis

• Photosynthesis occurs in two stages: the light-dependent stage, which takes place in the thylakoids, and the light-independent stage, which takes place in the stroma
• During the light-dependent stage of photosynthesis:
  • Reduced NADP is produced when hydrogen ions combine with the carrier molecule NADP using electrons from the photolysis of water
  • ATP is produced (from ADP and Pi by ATP synthase in a process called photophosphorylation (ADP + Pi → ATP)
  • Photophosphorylation uses the proton (H+) gradient generated by the photolysis of water
  • Energy from ATP and hydrogen from reduced NADP are passed from the light-dependent stage to the light-independent stage of photosynthesis
• The energy and hydrogen are used during the light-independent reactions (known collectively as the Calvin cycle) to produce complex organic molecules, including (but not limited to) carbohydrates, such as:
  • Starch (for storage)
  • Sucrose (for translocation around the plant)
  • Cellulose (for making cell walls)

Photosynthesis occurs in two, closely-linked stages: the light-dependent stage, which takes place in the thylakoids, and the light-independent stage, which takes place in the stroma