Valine is one of the 20 protein amino acids. Its chemical structure is (CH3)2CHCH(NH2)COOH. Its three-letter symbol is Val, and its one-letter symbol is V. Its molecular formula is C5H11NO2 which translates into a molecular weight of 117.15. Its isoelectric point is 5.96. Valine’s side chain is a simple hydrocarbon and is thus considered to be an apolar amino acid. Among the protein amino acids, alanine (C3H7NO2), leucine, and isoleucine (both C6H13NO2) are in the same group, but strangely, none of the isomers with four carbons (C4H9NO2) are protein amino acids. Valine has 11 nonprotein amino acid isomers, including norvaline and isovaline. All of them have been identified in the extract from Murchison meteorite. Valine is a hydrophobic amino acid and has often been used to make thermal microspheres from amino acids.