The process by which green plants convert sunlight into energy is called photosynthesis. During photosynthesis, plants use sunlight to transform carbon dioxide and water into glucose and oxygen. This process occurs primarily in the leaves, specifically in the chloroplasts, which contain the green pigment chlorophyll that captures sunlight. Photosynthesis is essential for life on Earth, as it produces oxygen and serves as the foundation of the food chain by providing energy for various organisms, including herbivores and carnivores.