What does deamination mean?
Deamination is the chemical process by which an amino group (–NH2) is removed from an organic molecule, most importantly from amino acids. It is central to metabolism: when the body breaks down surplus or worn-out proteins, deamination frees the carbon skeleton of each amino acid for energy production while releasing its nitrogen as ammonia, which the liver then converts into less toxic urea for excretion in urine. The term also appears in molecular biology, where spontaneous deamination of DNA bases such as cytosine is a frequent source of genetic damage and mutation. Because it describes a specific biochemical reaction rather than a general concept, the word belongs mainly to scientific registers — textbooks, research papers, and clinical discussion — rather than everyday speech. Its precise meaning, and its role in both nutrition and genome maintenance, make it an essential term for understanding how organisms handle protein turnover and nitrogen disposal.
nounThe removal of an amino group from a molecule, especially from amino acids. In living organisms it is a key step in the metabolism of amino acids and in the breakdown of excess nitrogen.
- Removal of an amino group (–NH2) from an organic compound, especially an amino acid, typically producing ammonia or transferring the nitrogen onward for excretion.
- In molecular biology, the spontaneous hydrolytic loss of an amino group from a DNA base such as cytosine or adenine, which can cause mutation.
"During oxidative deamination, glutamate releases its amino group as ammonia."
"The liver carries out most of the body's deamination of amino acids, converting their nitrogen into urea for excretion."
"Spontaneous deamination of cytosine is one of the most common forms of DNA damage that repair enzymes must continually correct."
Rarely pluralized; the plural appears chiefly in scientific contexts referring to distinct instances or types of the reaction.
"Several deaminations occur along the pathway before the nitrogen finally reaches urea."
Every day your body strips nitrogen from worn-out amino acids through deamination — the same chemical trick that turns cytosine into uracil if DNA isn't constantly repaired.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of deamination
Deamination derives from the prefix 'de-' (indicating removal) combined with 'amine' and the noun-forming suffix '-ation'. The word 'amine' itself was coined in the mid-19th century from 'ammonia', reflecting chemists' recognition that these compounds were related to ammonia by replacing hydrogen with organic groups. Deamination emerged as a term alongside late-19th- and early-20th-century advances in biochemistry, when scientists worked out how animals metabolize amino acids and dispose of nitrogen. It shares its root with cognates such as 'amination', 'amino', and 'ammonia'.
Related word forms
How deamination is actually used
A technical term used almost exclusively in biochemistry, physiology, and genetics; rare outside scientific writing. It is uncountable in general use, though occasionally pluralized when referring to different instances or types of the reaction.
Easily confused with deamination
Amination is the addition of an amino group to a molecule — the reverse process of deamination.