amino acid

[ uh-mee-noh as-id ]

/ əˈmi noʊ ˈæs ɪd /

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noun Biochemistry.

any of a class of organic compounds that contains at least one amino group, –NH2, and one carboxyl group, –COOH: the alpha-amino acids, RCH(NH2)COOH, are the building blocks from which proteins are constructed.

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Compare essential amino acid.

Origin of amino acid

First recorded in 1895–1900

Words nearby amino acid

aminate, Amindivi Islands, amine, amino, aminoacetic acid, amino acid, amino-acid dating, amino acids, amino acid sequence, aminoaciduria, aminobenzene

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use amino acid in a sentence

Additionally, he suspects organisms could have adopted the additional amino acids for reasons unrelated to oxidation.
Your ancestors might have been Martians|Charlie Wood|February 12, 2021|Popular-Science
The origins of life may have something to do with cosmic dust, because it actually delivered most of the intact amino acids and organic molecules of the Earth during the Late Bombardment .
What Dust From Space Tells Us About Ourselves|Natalie Wolchover|February 4, 2021|Quanta Magazine
Classically, a protein is imagined as a chain of amino acids that folds into a single stable configuration, one that evolution has selected over the ages for a particular function.
Some Proteins Change Their Folds to Perform Different Jobs|Viviane Callier|February 3, 2021|Quanta Magazine
A protein is a polypeptide chain of amino acids, letters in the 20-character protein “alphabet” that code for a particular protein structure and purpose.
The Dangerous Evolution of the Coronavirus - Issue 95: Escape|Brian Gallagher|January 28, 2021|Nautilus

This involved swapping out some of the amino acids along that PET docking site for others.
Chemists are reimagining recycling to keep plastics out of landfills|Maria Temming|January 27, 2021|Science News
I write the lyrics and work with Murv Douglas from Lords of Acid.
Porn Stars on the Year in Porn: Drone Erotica, Belle Knox, and Wild Sex|Aurora Snow|December 27, 2014|DAILY BEAST
During the height of his disenchantment, he visited his hometown where an old friend gave him some liquid acid.
DJ Spooky Wants You To Question Everything You Know About Music, Technology, and Philosophy|Oliver Jones|December 27, 2014|DAILY BEAST
Eggs, he says, are a good source of cysteine, an amino acid that helps the liver break down alcohol faster.
5 Hangover Cures to Save You After a Few Too Many|DailyBurn|December 19, 2014|DAILY BEAST
This at-home blood test kit gives a full reading of antioxidant, fatty acid, or vitamin panels.
Nothing Says I Love You Like Data|The Daily Beast|December 8, 2014|DAILY BEAST
The recent spate of acid attacks on women is only the latest manifestation of this dangerous trend.
The Nuclear Deal That Iran’s Regime Fears Most|Djavad Khadem|November 22, 2014|DAILY BEAST
There are a number of bacilli, called acid-fast bacilli, which stain in the same way as the tubercle bacillus.
A Manual of Clinical Diagnosis|James Campbell Todd
The amount of the other purin bodies together is about one-tenth that of uric acid.
A Manual of Clinical Diagnosis|James Campbell Todd
Uric acid is decreased before an attack of gout and increased afterward, but its etiologic relation is still uncertain.
A Manual of Clinical Diagnosis|James Campbell Todd
An increase is also noted in the uric-acid diathesis and in diseases accompanied by respiratory insufficiency.
A Manual of Clinical Diagnosis|James Campbell Todd
Indol is absorbed and oxidized into indoxyl, which combines with potassium and sulphuric acid and is thus excreted.
A Manual of Clinical Diagnosis|James Campbell Todd

British Dictionary definitions for amino acid

amino acid

noun

any of a group of organic compounds containing one or more amino groups, -NH 2, and one or more carboxyl groups, -COOH. The alpha-amino acids RCH(NH 2)COOH (where R is either hydrogen or an organic group) are the component molecules of proteins; some can be synthesized in the body (nonessential amino acids) and others cannot and are thus essential components of the diet (essential amino acids)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for amino acid

amino acid

Any of a large number of compounds found in living cells that contain carbon, oxygen, hydrogen, and nitrogen, and join together to form proteins. Amino acids contain a basic amino group (NH2) and an acidic carboxyl group (COOH), both attached to the same carbon atom. Since the carboxyl group has a proton available for binding with the electrons of another atom, and the amino group has electrons available for binding with a proton from another atom, the amino acid behaves as an acid and a base simultaneously. Twenty of the naturally occurring amino acids are the building blocks of proteins, which they form by being connected to each other in chains. Eight of those twenty, called essential amino acids, cannot be synthesized in the cells of humans and must be consumed as part of the diet. The remaining twelve are nonessential amino acids.