Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy. During this process, these organisms use sunlight, carbon dioxide from the air, and water to produce glucose and oxygen. The green pigment chlorophyll in plant cells captures sunlight, making photosynthesis possible. This process is essential for life on Earth, as it provides the oxygen we breathe and serves as the foundation of the food chain. The glucose produced during photosynthesis is used by plants for energy and growth, while animals and humans rely on plants for food and oxygen.