valine

A nonpolar amino acid with the formula (CH₃)₂CHCH(NH₂)COOH. Valine is synthesized from pyruvate via α-ketoisovalerate. The degradation of valine is extremely complex, leading eventually to proprionyl CoA and thence to succinyl CoA. Methionine, leucine, and isoleucine also degrade to proprionyl CoA; the last sequence of reactions to succinyl CoA is thus common to all four amino acids.