Plants use a process known as photosynthesis to convert sunlight into chemical energy. During photosynthesis, plants use chlorophyll, the green pigment in leaves, to capture sunlight. They absorb carbon dioxide from the air and water from the soil, and through a series of chemical reactions, sunlight energy is transformed into glucose, a type of sugar used as food. Oxygen is released as a byproduct of this process. Photosynthesis is essential for life on Earth, as it not only fuels plant growth but also produces the oxygen necessary for most living organisms.