The amino acids are the molecules where we can found the carboxyl group (-[tex]COO^{-}[/tex]), amino group (-[tex]NH_{2}[/tex]), hydrogen atom (H) and a residual R-group. On the structure of the residual R-group the name of the amino acid depends. Like if R is hydrogen (H) the amino acid is alanine; If R- group is a phenyl group i.e. [tex]-C_{6}H_{5}[/tex], the compound is called phenyl alanine. The structure of the general amino acid skeleton can be shown as-
