Preferred term
amino acid
Is replaced by
Definition
- [Henderson's] n. any of a class of compounds of the general formula RCH(NH2)COOH (α-amino acids) where R is a distinctive side chain. Side chains vary from the single hydrogen atom of glycine to the aromatic side chains of tryptophan and phenylalanine and the sulphur-containing side chains of cysteine and methionine. Proteins are composed of amino acids covalently linked together through their amino and carboxyl groups into a polypeptide chain with the side chains projecting from the covalently linked backbone. Amino acids can occur as optically active d- and l-isomers, of which only l-isomers are found in proteins. Around 20 different amino acids are present in proteins, all of which can be synthesized by autotrophs but which in heterotrophs are chiefly obtained by breakdown of dietary protein. Amino acids are also biosynthetic precursors of many important molecules such as purines, pyrimidines, histamine, thyroxine, adrenaline, melanin, serotonin, the nicotinamide ring and porphyrins among others. see Fig. 4 and individual entries for each amino acid.
Broader concept
Scope note
- US LTER controlled vocabulary
Creator
- herbert.schentz@umweltbundesamt.at
URI
http://vocabs.lter-europe.net/EnvThes/USLterCV_29