The acidic amino acids contain one amino and two carboxyl groups each, e.g. glutamic acid and aspartic acid.
The basic amino acids have two amino groups and one carboyxl group, e.g. lysine and arginine.
The neutral amino acids have one amino group and one carboxyl group e.g. alanine, glycine, valine and phenylalanine.
(1) These act as building blocks of proteins and help in their synthesis by polymerisation.
(2) Some of the amino acids are converted into useful biologically active compounds .
(3) Non-protein amino acids serve as different components of antibiotics.