Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These electron donors can be organic or inorganic molecules.
5 Must Know Facts For Your Next Test
Chemotrophs are classified into two groups: chemoautotrophs and chemoheterotrophs.
Chemoautotrophs use carbon dioxide as a carbon source, whereas chemoheterotrophs require organic carbon sources.
Many prokaryotes, including bacteria and archaea, are chemotrophs.
Chemolithotrophs oxidize inorganic molecules such as hydrogen sulfide or ammonia for energy.
Energy production in chemotrophs often involves processes like cellular respiration.
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Related terms
Phototrophs: Organisms that obtain energy from light through photosynthesis.
Autotrophs: Organisms that produce their own food from inorganic substances using light or chemical energy.
Heterotrophs: Organisms that rely on consuming organic compounds for both energy and carbon.