Which group do nonpolar amino acids belong to?

Nonpolar amino acids are categorized as such because of their hydrophobic side chains, which do not interact favorably with water. These amino acids typically consist of aliphatic or aromatic side chains that lack polar functional groups. This hydrophobic nature means that nonpolar amino acids tend to aggregate together in aqueous environments, stabilizing the structure of proteins by minimizing their exposure to water.

In this context, nonpolar amino acids play crucial roles in protein folding and structure, often forming the core of protein tertiary structures, where they are shielded from the aqueous surroundings. This characteristic distinguishes them clearly from polar or charged amino acids, which have side chains that can form hydrogen bonds with water or carry charged groups. Thus, placing nonpolar amino acids in the nonpolar category accurately reflects their chemical nature and behavior in biological systems.