Which organic molecule contains both an amine and a carboxyl group?

Proteins are organic molecules that contain both an amine group (−NH2) and a carboxyl group (−COOH). The presence of these functional groups is essential for proteins, as they are composed of amino acids, the building blocks of proteins. Each amino acid features one central carbon atom bonded to an amine group, a carboxyl group, a hydrogen atom, and a variable side chain or R group that determines the specific properties of each amino acid.

This structure is fundamental for protein synthesis in biological processes, as these amino acids link together through peptide bonds to form polypeptide chains. The unique combinations and arrangements of amino acids result in diverse protein structures and functions within living organisms.

In contrast, carbohydrates primarily consist of sugar molecules and do not possess both an amine and carboxyl group in their basic structures. Lipids are hydrophobic molecules primarily made up of fatty acids and glycerol, lacking these functional groups as well. Nucleic acids, such as DNA and RNA, are composed of nucleotides featuring a sugar, a phosphate group, and a nitrogenous base, but they also do not have a structure that includes both an amine and a carboxyl group directly. Therefore, proteins are