In which part of photosynthesis is oxygen produced?

Oxygen is produced during the process of photosynthesis specifically when water molecules are split apart. This process occurs in the light-dependent reactions, which take place in the thylakoid membranes of the chloroplasts. When light energy is absorbed by chlorophyll, it energizes electrons; this energy is used to split water molecules into hydrogen ions and oxygen gas. The oxygen produced is then released into the atmosphere as a byproduct.

The Calvin cycle, where carbon dioxide is converted into glucose, does not produce oxygen directly. Instead, it utilizes products generated from the light-dependent reactions. Absorbing carbon dioxide is a part of photosynthesis, but it does not result in the production of oxygen. Lastly, respiration, which occurs at night, involves the consumption of oxygen rather than its production. Overall, the process of splitting water during the light-dependent reactions is essential for generating the oxygen we breathe.