Here's how it works:
1. Light-dependent reactions: Sunlight is captured by chlorophyll in the chloroplasts of plant cells. This energy is used to split water molecules.
2. Oxygen release: The splitting of water releases electrons, hydrogen ions (H+), and oxygen gas (O₂).
3. Byproduct: The oxygen gas is a byproduct of this process and is released into the atmosphere.
In summary, the oxygen we breathe comes from the water molecules that plants use during photosynthesis.
