Each of the 20 amino acids has a specific side chain ... Other amino acids avoid water and are called hydrophobic, such as isoleucine, phenylalanine, and valine. The amino acid cysteine has ...

This image illustrates the general structure of an amino acid.The central carbon atom (C) is bonded to a hydrogen atom (H), an amino group (NH2), a carboxyl group (COOH), and a variable side chain (R ...

Charged amino acid side chains can form ionic bonds, and polar amino acids are capable of forming hydrogen bonds. Hydrophobic side chains interact with each other via weak van der Waals interactions.