Classification of Amino Acids Based on R Groups

Amino acids are the building blocks of proteins and play crucial roles in various biological processes. Each amino acid has a specific side chain (R group) that determines its characteristics and function. Among the 20 standard amino acids, they can be classified into categories such as nonpolar, polar, basic, and acidic. The structure and properties of these amino acids influence protein folding and function.

Consider an amino acid with a side chain that contains a carboxyl group (-COOH). Which of the following statements is true regarding this amino acid?