Two functional groups are found in all amino acids. These functional groups are the amino group (-NH2) and the carboxyl group (-COOH). The hydrogen atom of the carboxyl group can be broken off quite easily; this gives amino acids their acidic properties.
No. A functional group is a group of atoms that impart particular properties to an organic compound. For example, the hydroxyl group, -OH, is the functional group of an alcohol, and the carboxyl group, -COOH, is the functional group of an organic acid.