Photosynthesis is the process plants use to release oxygen. During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen, using sunlight as energy. Chlorophyll, the green pigment in chloroplasts, captures sunlight, initiating a series of chemical reactions. The overall reaction can be summarized by the equation: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2. The released oxygen is a byproduct and is essential for most living organisms, as it is necessary for cellular respiration. Photosynthesis plays a crucial role in maintaining the Earth's oxygen levels and supports life by providing energy for the food chain.