Photosynthesis is a process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy stored in glucose. This process occurs in the chloroplasts of plant cells and involves the absorption of sunlight, carbon dioxide fixation, and the release of oxygen. The expected answer should provide a detailed explanation of the steps involved in photosynthesis, including the role of chlorophyll and other pigments, the light-dependent and light-independent reactions, and the overall equation for photosynthesis. It should also emphasize the importance of photosynthesis in providing oxygen, food, and energy for the ecosystem, and how it maintains the balance of gases in the atmosphere.