Which functional groups are present in amino acids?

Amino acids are organic molecules that serve as the building blocks of proteins. Each amino acid contains two key functional groups: an amino group and a carboxyl group. The amino group, represented as -NH2, contributes to the basic properties of amino acids, allowing them to act as bases by accepting protons. Conversely, the carboxyl group, designated as -COOH, provides acidic characteristics since it can donate protons (H+ ions) in solution.

The presence of both these functional groups enables amino acids to participate in various chemical reactions, including peptide bond formation, which is critical for protein synthesis. This unique combination of functional groups is what differentiates amino acids from other types of organic compounds.

Although the other options mention various functional groups, none of them correctly identify the combination of functional groups that characterize all amino acids. Therefore, the correct association of the amino group and carboxyl group is essential for understanding the structure and function of amino acids in biological systems.