The process by which plants make their own food is called photosynthesis. During photosynthesis, plants convert light energy, primarily from the sun, into chemical energy stored in glucose, a sugar molecule. This process occurs mainly in the chloroplasts of plant cells, where chlorophyll captures sunlight. Carbon dioxide from the air and water from the soil are also essential ingredients in this process. Oxygen is released as a byproduct, making photosynthesis crucial for sustaining life on Earth, as it provides the oxygen we breathe and is the foundation of the food chain.