Photosynthesis is the process by which only plants convert sunlight into food (sugar). This process occurs primarily in the leaves where carbon dioxide, water, and sunlight are combined. This produces food and oxygen. The food all plants produce is a form of sugar (glucose). Each biome requires plants to provide energy to later levels of the biome's food chain. Later levels include herbivores, carnivores, and top predators. The process converts light energy=>food (chemical energy).