<unk>  (abbreviated as<unk>  or<unk>  is an α-amino acid with the<unk> ormula HO2CCH(NH2)CH2C6H5. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain.  The codons<unk> or L-phenylalanine are UUU and UUC. It is a white, powdery solid.  L-Phenylalanine (LPA) is an electrically-neutral amino acid, one of the twenty common amino acids used to biochemically<unk> orm proteins, coded<unk> or by DNA.
Phenylalanine
Cysteamine 
Arginine
Citrulline
Asparagine
Tyrosine
Ethionine
Xanthine