The primary element found in amino acids is carbon, which serves as the backbone for the structure of all amino acids. Each amino acid contains both an amino group (-NH₂) and a carboxyl group (-COOH), along with a unique side chain, known as the R group, that determines its specific characteristics. Carbon's ability to form four covalent bonds allows for the complex structures of amino acids and proteins. Other essential elements present in amino acids include hydrogen, oxygen, and nitrogen.