Light-dependent reactions

Definition

The light-dependent reactions are the first stage of photosynthesis where light energy is converted into chemical energy in the form of ATP and NADPH. These reactions take place within the thylakoid membranes of the chloroplasts.

5 Must Know Facts For Your Next Test

1. Light-dependent reactions occur in the thylakoid membranes.
2. The primary products are ATP and NADPH, which are used in the Calvin cycle.
3. Water molecules are split (photolysis) to release oxygen as a byproduct.
4. Photosystems I and II play crucial roles in capturing light energy.
5. These reactions require sunlight to initiate the energy conversion process.

Review Questions

• Where do light-dependent reactions take place within the cell?
• What are the main products of light-dependent reactions?
• What role do Photosystems I and II play in these reactions?

Related terms

Calvin Cycle: This is the second stage of photosynthesis where ATP and NADPH produced from the light-dependent reactions are used to synthesize glucose.

Thylakoid Membrane: The site within chloroplasts where light-dependent reactions occur, containing photosystems and electron transport chains.

Photophosphorylation: The process of converting ADP to ATP using sunlight during the light-dependent reactions.