troph

Troph is a combining form derived from the Greek trophe, meaning nourishment or feeding. In biology, troph- or tropho- is used to indicate nutritional mode or the source of energy for an organism.

Common terms include autotroph (an organism that obtains energy and builds biomass from inorganic sources, typically carbon dioxide) and heterotroph (an organism that requires organic molecules for carbon or energy). Energy may come from light in phototrophs or from chemical compounds in chemotrophs; additional categories include lithotrophs (inorganic electron donors) and organotrophs (organic electron donors). Mixotrophs use more than one strategy.

In ecology, "trophic" describes feeding relationships and energy flow. Trophic levels traditionally include producers (autotrophs), primary consumers, secondary and higher-level consumers, and decomposers. Trophic pyramids illustrate how energy declines across levels, and trophic cascades describe how changes at one level can affect others in the food web.

In broader biology, trophic applies to growth and nutrition. Trophic factors promote development, and atrophy refers to wasting away due to loss of nourishment. The root also appears in terms such as tropho- to describe feeding stages in protists and parasites (for example, trophozoite).