The predominant gas produced during photosynthesis is oxygen. This process occurs in green plants, algae, and certain bacteria, which utilize sunlight to convert carbon dioxide and water into glucose and oxygen. During photosynthesis, chlorophyll absorbs light energy, facilitating the conversion of these raw materials. The overall reaction can be summarized as carbon dioxide plus water, in the presence of sunlight, yielding glucose and oxygen as a byproduct. This release of oxygen is critical for the survival of aerobic organisms, contributing to the Earth's atmosphere and supporting life.