Imagine you could build your own food just by standing in the sunshine. That’s exactly what plants do. The trick is called photosynthesis, and it’s one of the most powerful biological processes anywhere on Earth.
Inside a plant’s leaves are tiny structures called chloroplasts, packed with a green pigment called chlorophyll. Chlorophyll absorbs sunlight, and that energy powers a chemical reaction that combines carbon dioxide from the air with water from the soil to produce glucose - sugar. The plant uses the sugar as food. As a happy byproduct, the reaction releases oxygen into the air.
Photosynthesis is the foundation of almost every food chain on the planet. Even meat-eaters depend on it: they eat animals that ate plants, which got their energy from sunlight. About half of the oxygen you breathe also comes from photosynthesis - most of it produced by tiny ocean plants called phytoplankton. Without photosynthesis, Earth would have no oxygen-rich atmosphere, no plant or animal life, and effectively no food. Plants are quietly running the world.
