Which is not a product of light reaction?

The correct answer is H₂O

Explanation:

• The light reaction, also known as the light-dependent reaction, is the first stage of photosynthesis where light energy is converted into chemical energy.
• During this process, light energy is captured by chlorophyll and used to produce ATP and NADPH, which are used in the Calvin cycle, the second stage of photosynthesis.
• Water (H₂O) is split into oxygen, protons, and electrons in a process known as photolysis. The electrons are used to replace those lost by chlorophyll in the light reaction.
  • NADPH: This is one of the main products of the light reaction. It is generated when the electrons from the water splitting process are ultimately transferred to NADP⁺, forming NADPH.
  • H₂O: This is not a product of the light reaction but rather a reactant. Water is consumed during the light-dependent reactions, where it is split into oxygen, protons, and electrons.
  • O₂: This is a product of the light reaction. Oxygen is released into the atmosphere as a byproduct of the splitting of water molecules during photolysis.
  • ATP: This is another key product of the light reaction. The energy from light is used to convert ADP and inorganic phosphate into ATP via a process called photophosphorylation.