Amino acids are the main building blocks of proteins and in plants they act a number of additional functions in regulation of metabolism and the transport and storage of nitrogen.
Amino acids are the initial products of nitrogen assimilation.
1. Reductive amination:
Involves transfer of amino group from one amino acid to the keto group of keto acid. From glutamic acid other 17 amino acids are formed through transamination in the presence of enzyme transaminase.
Amino acids, glutamic acid and aspartic acid takes part in the formation of amides asparagine and glutamine. The hydroxyl part of the acid is replaced’ by any other NH, radical and this takes place in the presence of enzyme glutamine synthetase or asparagine synthetase.
Proteins are nitrogenous compounds containing C, H, O and N. Sometimes P and S are also associated with protein. The amino group of one amino acid attaches to the carboxyl group of its neighbour amino acid. In this process a molecule of water is eliminated and peptide bond (NH- CO-) is formed.
Proteins consist of one or more chains called polypeptide chains each of which consists of hundreds of amino acids.