What does autotrophy mean?
Autotrophy is the biological mode of nutrition in which an organism manufactures its own organic matter from simple inorganic substances such as carbon dioxide and water, rather than obtaining food by eating other organisms. The energy needed for this synthesis comes either from sunlight, as in photosynthesis, or from chemical reactions involving inorganic compounds such as hydrogen sulfide or iron, a process known as chemosynthesis. Organisms capable of this are called autotrophs, and they include plants, algae, cyanobacteria, and certain bacteria found in environments ranging from forest canopies to deep-sea hydrothermal vents. Because autotrophs produce the organic material on which all other life ultimately depends, autotrophy underpins virtually every ecosystem on Earth. The term is technical, appearing mainly in biology and ecology, where it contrasts with heterotrophy, the consumer-based nutrition of animals, fungi, and many microbes.
nounThe mode of nutrition in which an organism produces its own organic food from inorganic substances, using light or chemical energy rather than consuming other organisms.
- The biological condition or mode of nutrition in which an organism synthesizes its own organic compounds from carbon dioxide and other inorganic substances, using energy from light (photoautotrophy) or from chemical reactions (chemoautotrophy).
"Plants sustain themselves through autotrophy, converting sunlight and carbon dioxide into the sugars they need to grow."
"Through autotrophy, phytoplankton form the base of nearly every oceanic food web."
"Deep-sea bacteria survive near hydrothermal vents by means of chemoautotrophy, drawing energy from hydrogen sulfide instead of sunlight."
Rarely pluralized; the singular is almost always sufficient since the term denotes a general mode of nutrition rather than countable instances.
"Biologists distinguish several distinct autotrophies, including photoautotrophy and chemoautotrophy."
Every meal you have ever eaten traces back to autotrophy — without self-feeding organisms capturing sunlight or chemicals, there would be no food chain at all.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of autotrophy
The word autotrophy was coined in modern scientific usage from two ancient Greek roots: 'autos', meaning self, and 'trophē', meaning nourishment or food — literally, self-nourishment. It belongs to a productive family of biological terms built on '-trophy' or '-trophic', including atrophy, dystrophy, and eutrophic, which likewise describe states or processes of feeding and growth. The related adjective autotrophic and noun autotroph were formed directly from it as scientists formalized the distinction between self-feeding and other-feeding organisms.
Related word forms
How autotrophy is actually used
A technical term used almost exclusively in biology, ecology, and environmental science; it does not appear in everyday conversation. In casual scientific writing, speakers more often refer to 'autotrophs' (the organisms) than to 'autotrophy' (the process or condition) itself.
Easily confused with autotrophy
Heterotrophy is the opposite nutritional strategy, in which an organism obtains its food by consuming other organisms or organic matter rather than making it from inorganic raw materials.
Mixotrophy describes organisms that combine both strategies, using autotrophy and heterotrophy together depending on conditions.