amino acid

[ uh-mee-noh as-id ]

noun

, Biochemistry.

1. any of a class of organic compounds that contains at least one amino group, –NH 2 , and one carboxyl group, –COOH: the alpha-amino acids, RCH(NH 2 )COOH, are the building blocks from which proteins are constructed.

amino acid

noun

1. 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 )

amino acid

1. 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 (NH 2 ) 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.

Word History and Origins

Origin of amino acid¹

First recorded in 1895–1900

Example Sentences

Additionally, he suspects organisms could have adopted the additional amino acids for reasons unrelated to oxidation.

From 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 .

From 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.

From 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.

From Nautilus

This involved swapping out some of the amino acids along that PET docking site for others.

From Science News

Eggs, he says, are a good source of cysteine, an amino acid that helps the liver break down alcohol faster.

From The Daily Beast

Unlike coffee, tea has an amino acid that is associated with calmness: Theanine.

From The Daily Beast

The premise is this: turkey is chock-full of a soporific essential amino acid, tryptophan, one of the 22 essential amino acids.

From The Daily Beast

Peptides provide a cheese with its distinct flavor, based on the configuration of these amino-acid chains.

From The Daily Beast

It is not always possible to specify exactly how much of a mineral, a vitamin, or an amino acid a person requires for good health.

From Project Gutenberg

To make human protein we must not only have all the amino acid ingredients, but we must also have enough of every one.

From Project Gutenberg