Autotrophs, meaning “self-feeders,” make their own food, which means that they are capable of sustaining vital processes without consuming organic molecules. These organisms make their own organic compounds from inorganic sources. Carbon, for example, can be obtained from the CO2 in the air. Other substances, such as sulfur or iron, can be obtained from environmental sources like sunlight. Autotrophs that harness sunlight for energy are called photoautotrophs. Chemoautotrophs get their energy from chemicals. Plants are photoautotrophs. They use their chloroplasts to convert captured light energy into chemical energy stored in the form of sugar.