A 'heterotroph' (
Greek '''heterone''' = (an)other and '''trophe''' = nutrition) is an
organism that requires
organic substrates to get its carbon for growth and development. A heterotroph is known as a 'consumer' in the food chain. Contrast with
autotrophs which use inorganic
carbon dioxide or
bicarbonate as sole carbon source. All
animals are heterotrophic, as well as
fungi and many
bacteria. Some
parasitic plants have also turned fully or partially heterotrophic, whereas
carnivorous plants use their flesh diet to augment their nitrogen supply, but are still autotrophic.
Heterotrophs are unable to synthesize organic,
carbon based compounds independently from the inorganic environment's sources (e.g.
Animalia, unlike
Plantae, cannot
photosynthesize) and therefore must obtain their nutrition from another heterotroph or an
autotroph.
For a
species to be termed a heterotroph, it must obtain its carbon from
organic compounds. If it obtains
nitrogen from
organic compounds, but not
energy, it will be deemed an
autotroph. If a
species obtains
carbon from
organic compounds then there are two possible subtypes of these heterotrophs:
★
photoheterotroph — obtains
energy from light and must obtain carbon in an organic form
★
chemoheterotroph — obtains
energy from the the consumption of organic molecules and an organic form of carbon
In simpler terminology, a heterotroph is an organism that is incapable of making its own food from light or
inorganic compounds, and feeds on organisms or the remains of other organisms to get its necessary energy to survive.
See also
★
Myco-heterotrophy
★
Organotroph
★
Mixotrophic
★
Primary nutritional groups