Which group of amino acids is characterized by their nonpolar side chains?

Amino acids with nonpolar side chains are classified as hydrophobic, which means they do not interact well with water. The hydrophobic properties arise from the structure of the side chains, which typically consist of hydrocarbons or other nonpolar groups that do not form hydrogen bonds with water, leading to their tendency to aggregate away from aqueous environments. This characteristic plays a crucial role in protein folding and stability, as hydrophobic amino acids often cluster together in the interior of proteins, away from the water, while polar (hydrophilic) and charged amino acids are more likely to be found on the surface, interacting with the aqueous environment.

In this context, the terminology for the other groups reflects different chemical characteristics of amino acids. Hydrophilic amino acids typically contain polar or charged side chains that can form hydrogen bonds with water. Charged amino acids possess side chains that are ionized at physiological pH and carry a charge, influencing their solubility and function in proteins. Uncharged amino acids, while they may have polar side chains, do not possess a net charge. Thus, the distinction between hydrophobic and the other categories, like hydrophilic, charged, and uncharged, clarifies the classification based on the interactions of these molecules with water