What is "heterotroph"

1900, from hetero- + Greek trophos "feeder" (see -trophy). Related: Heterotrophic (1893).

n. (context ecology English) An organism which requires an external supply of energy in the form of food as it cannot synthesize its own.

n. an organism that depends on complex organic substances for nutrition

A heterotroph (; heteros = "another", "different" and trophe = "nutrition") is an organism that cannot fix carbon and uses organic carbon for growth. Heterotrophs can be further divided based on how they obtain energy; if the heterotroph uses light for energy, then it is considered a photoheterotroph, while if the heterotroph uses chemical energy, it is considered a chemoheterotroph.

Heterotrophs contrast with autotrophs, such as plants and algae, which can use energy from sunlight ( photoautotrophs) or inorganic compounds ( lithoautotrophs) to produce organic compounds such as carbohydrates, fats, and proteins from inorganic carbon dioxide. These reduced carbon compounds can be used as an energy source by the autotroph and provide the energy in food consumed by heterotrophs. Ninety-five percent or more of all types of living organisms are heterotrophic, including all animals and fungi and most bacteria and protists.