Before revision: Phenylalanine|139x139px Tryptophan|145x145px Tyrosine|140x140pxAn aromatic amino acid is an amino acid that includes an aromatic ring.
After revision: Histidine|139x139pxPhenylalanine|139x139px Tryptophan|145x145px Tyrosine|140x140pxAn aromatic amino acid is an amino acid that includes an aromatic ring.