What Are the Reactants and Products of the Light Reactions?

The light reactions, also known as the light-dependent reactions, are the first stage of photosynthesis. They occur in the thylakoid membranes of the chloroplasts in plant cells. Here are the reactants and products involved in the light reactions:

Reactants:

• Water (H₂O): Water molecules are split to provide electrons.
• Light Energy: Sunlight is absorbed by chlorophyll and other pigments.
• NADP⁺: Nicotinamide adenine dinucleotide phosphate, which accepts electrons.
• ADP and Inorganic Phosphate (P_i): Used to produce ATP.

Products:

• Oxygen (O₂): Released as a byproduct when water molecules are split.
• ATP (Adenosine Triphosphate): Energy currency of the cell, produced from ADP and inorganic phosphate.
• NADPH: Formed when NADP⁺ accepts electrons and a hydrogen ion.

In summary, the light reactions convert light energy into chemical energy in the form of ATP and NADPH, which are then used in the Calvin cycle to produce sugars.