The process of photosynthesis is used by plants, algae, and some bacteria to convert light energy into chemical energy in the form of glucose. Using sunlight, carbon dioxide from the atmosphere, and water absorbed by the roots, these organisms synthesize their food while releasing oxygen as a byproduct. The process occurs primarily in chloroplasts, where chlorophyll captures sunlight. Photosynthesis is crucial for life on Earth, as it forms the foundation of the food chain and provides oxygen necessary for respiration in most living organisms.