Final answer:
Oxygen is produced during the light-dependent reactions of photosynthesis when water molecules are split by the energy absorbed from sunlight by chlorophyll, resulting in the release of oxygen, hydrogen ions, and electrons.
Step-by-step explanation:
During the light-dependent reaction of photosynthesis, oxygen is made from the breakdown of water (H2O). This process occurs when pigment molecules, such as chlorophyll, absorb energy from sunlight. The energy from light causes a rearrangement of electrons in the chlorophyll, which eventually leads to the oxidation of water. When water molecules are split apart, they release oxygen gas, hydrogen ions, and electrons. The released electrons are then used to replace those lost by chlorophyll, enabling it to absorb more light and continue the process. The oxygen molecules produced are released as a byproduct into the atmosphere. Meanwhile, the hydrogen ions contribute to the generation of ATP and NADPH, which are energetic molecules used in the subsequent light-independent reactions to synthesize carbohydrates.
The breakdown of water molecules during the light-dependent reaction of photosynthesis produces oxygen. This process occurs in the thylakoid membranes of the chloroplasts. When light energy is absorbed by chlorophyll molecules, they become energized and donate electrons to an electron transport chain. As a result, water molecules are split, releasing oxygen gas as a byproduct.