We are offering methionine. Methionine is an α-amino acid with the chemical formula ho₂cchch₂ch₂sch₃. This amino acid is classified as nonpolar as it has a straight side chain that possess a s-methyl thioether at the γ-carbon. It is an essential amino acid in all metazoa. Formula: c5h11no2s molar mass: 149.21 gmol melting point: 281 °c iupac id: 2-amino-4-(methylthio)butanoic acid density: 1.34 gcm³ soluble in: water contact for more details.