During What Stage of Photosynthesis is O2 Produced?

Oxygen (O₂) is produced during the light-dependent reactions of photosynthesis. These reactions take place in the thylakoid membranes of the chloroplasts.

Here’s a brief explanation of the process:

• Light energy is absorbed by chlorophyll and other pigments in the thylakoid membranes.
• This energy is used to split water molecules (H₂O) into oxygen (O₂), protons (H⁺), and electrons (e^–). This process is known as photolysis.
• The oxygen (O₂) is released as a byproduct, while the protons and electrons are used to generate ATP and NADPH, which are essential for the next stage of photosynthesis, the Calvin cycle.

In summary, the production of oxygen occurs during the light-dependent reactions, specifically through the process of photolysis, where water molecules are split using light energy.