The process by which plants make their food is called photosynthesis. During photosynthesis, plants utilize sunlight, carbon dioxide from the atmosphere, and water from the soil to produce glucose, a form of sugar that serves as energy for the plant. Oxygen is released as a byproduct of this process. Photosynthesis primarily occurs in the chloroplasts of plant cells, which contain chlorophyll, the green pigment that absorbs sunlight. This vital process not only sustains the plants but also supports life on Earth by providing oxygen and serving as the foundation of the food chain.