What does amino mean?
Amino is a technical adjective used in chemistry and biochemistry to describe compounds containing an amino group — a nitrogen atom bonded to two hydrogen atoms (–NH₂) attached to a molecule. Its most familiar appearance is in the phrase 'amino acid', referring to the organic building blocks that link together to form proteins; other examples include amino sugars and amino alcohols. The word functions almost exclusively attributively, appearing before the noun it modifies, and it belongs firmly to scientific register rather than everyday speech. Derived ultimately from 'amine', which itself traces back through 'ammonia', it reflects the nineteenth-century development of organic chemistry's systematic nomenclature. For general readers, encountering 'amino' is usually a signal that the discussion concerns proteins, nutrition, or molecular biology, where the term is indispensable for describing how nitrogen enters the structures of life.
adjectiveRelating to or containing the chemical group –NH₂ (an amino group), especially as a substituent attached to an organic compound. It is used almost exclusively in chemistry and biochemistry to describe such compounds.
- Relating to or containing the amino group –NH₂, especially in organic chemistry (e.g. amino acids, amino sugars).
"Glycine is the simplest of the amino acids that make up proteins."
"The lab synthesized a new amino compound for testing."
"Proteins are chains of amino acids linked by peptide bonds."
Every protein in your body is stitched together from just twenty-odd building blocks — and every one of them is an 'amino' something.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of amino
The word amino derives from amine, coined in the nineteenth century within the emerging system of organic chemical nomenclature. Amine itself was formed from ammonia, whose name ultimately traces to sal ammoniac (ammonium chloride), so called because it was historically obtained near the temple of Jupiter Ammon in ancient Libya. Related terms sharing this lineage include amine, ammonia, and ammonium.
How amino is actually used
Amino is a technical adjective used almost entirely within chemistry, biochemistry, and nutrition writing; it rarely appears outside scientific contexts. It typically functions attributively (amino acid, amino group) rather than predicatively. The pluralUsage field does not apply since it is not a noun.
Easily confused with amino
An amine is the noun naming a class of nitrogen-containing compounds, while amino is an adjective describing compounds that contain an amino group (–NH₂).