amino


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amino

 [ah-me´no, am´ĭ-no]
the monovalent radical NH2, when not united with an acid radical.
amino acid any of a class of organic compounds containing the amino (NH2) and the carboxyl (COOH) groups, occurring naturally in plant and animal tissues and forming the chief constituents of protein. Twenty amino acids are necessary for protein synthesis. Eleven (the nonessential amino acids) can be synthesized by the human body and thus are not specifically required in the diet: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine. Nine (the essential amino acids) cannot be synthesized by humans and thus are required in the diet: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
 Structural formulas for some representative amino acids. From Applegate, 2000.


Protein foods that provide the essential amino acids are known as complete proteins; these include proteins from animal sources, such as meat, eggs, fish, and milk. Proteins that cannot supply the body with all the essential amino acids are known as incomplete proteins; these are the vegetable proteins most abundantly found in legumes (peas and beans), as well as certain grains. Because different incomplete proteins lack different amino acids, specific combinations can provide all of the essential amino acids.

In certain inherited or acquired disorders of metabolism, specific amino acids accumulate in the blood (aminoacidemia) or are excreted in excess in the urine (aminoaciduria). Urinary amino acid levels are increased in liver disease, muscular dystrophies, phenylketonuria (PKU), lead poisoning, and folic acid deficiency.
References in periodicals archive ?
Key words: Amino acids Effluents Irrigated Land Environmental Pollution.
For degree of centrality point of view we observe that the amino acids R and S have highest degree of centrality.
The researchers say the amino acids formed in space may have kick-started life on Earth during this time.
For a limited period of time INEOS is permitted to use the DSM brand name Uramex [R] for the amino products involved.
This amino acid combines with different sugars and produces a seasoning with a pleasant meat flavor.
The amino acid score was calculated in three different ways.
The extraterrestrial origin of these amino acids also can't be explained by a familiar process in which organic compounds react with ammonia, hydrogen cyanide and water to produce the protein building blocks.
Finding amino acids in the asteroid fragments was surprising for many reasons.
"Finding them in this type of meteorite suggests that there is more than one way to make amino acids in space, which increases the chance for finding life elsewhere in the Universe," he said.
"This is the first demonstration that an amino acid mixture can increase survival in mice," said study leader Dr Enzo Nisoli, from the University of Milan in Italy.
Among others, the main amino acids were, valine (5.4 g/L by UAF AL17), glutamic acid (3.9 g/L by UAF AF21), lysine (3.8 g/L by UAF AM1-18), histidine (4.7 g/L by UAF AF6) and aspartic acid (3.9 g/L by UAF AF14).
Dietary proteins provide a source of the naturally occurring twenty amino acids, most importantly the nine essential amino acids.