Chemoautotrophy

Part of speech: noun

Definitions

1. A metabolic pathway in which certain organisms derive energy from inorganic substances while converting carbon dioxide into organic matter
2. A form of nutrition seen in some organisms that harnesses energy from chemical reactions involving non-organic compounds for carbon assimilation
3. A process where organisms obtain energy from inorganic chemical reactions and use carbon dioxide to create organic compounds

Etymology: Chemoautotrophy is a modern scientific coinage built from two parts: "chemo-", from the Greek "khymeia" (the root that also gave "chemistry"), and "autotrophy", from Greek words meaning "self" and "feeding." The second part is the older piece. Autotrophy describes organisms that make their own food from simple inorganic materials rather than eating other living things. The "chemo-" element points to the energy source. Instead of capturing sunlight as plants do, chemoautotrophs draw energy from chemical reactions, often by oxidising inorganic compounds such as hydrogen sulfide, ammonia or iron, and then use that energy to fix carbon dioxide into their own organic matter. The word thus combines a term for chemistry with a term for self-feeding life, describing a way of living that needs neither sunlight nor other organisms.