What is produced as a byproduct of light-dependent reactions?

During the light-dependent reactions of photosynthesis, which occur in the thylakoid membranes of chloroplasts, light energy is captured by chlorophyll and used to convert water molecules into oxygen, protons, and electrons. This process is known as photolysis of water. The light energy splits water, releasing oxygen as a byproduct into the atmosphere.

While glucose is produced later in the light-independent reactions (Calvin cycle), and carbon dioxide is used in the process rather than produced, the light-dependent reactions primarily focus on generating ATP and NADPH for the subsequent reactions, with oxygen being the significant byproduct. Thus, the production of oxygen during these reactions highlights the role of photosynthesis in contributing to the atmospheric oxygen levels essential for life on Earth.