it encodes 7 groups of isofunctional amino acids : 3 overlapping groups of non-polar amino acids 1 ) medium-size hydrophobic amino acids ( chiefly val , n-val and a-but ) , 2 ) small and medium-size non-polar amino acids ( chiefly ala val , n-val a-but and gly ) , 3 ) small non-polar amino acids ( gly , ala , a-but ) and 4 groups of polar amino acids -- 1 ) hydroxy -- +dicarbonic ( asp , glu , ser and thr ) , 2 ) dicarbonic ( asp and glu ) , 3 ) hydroxy ( ser and thr ) and 4 ) basic ( arg and lys ) .
C0002520
amino acids
C0017890
gly