An enzyme is a type of biomolecule that is primarily a protein. Enzymes are proteins made up of amino acids linked together in polypeptide chains, and they function as biological catalysts to speed up specific chemical reactions in cells without being consumed in the process. Some enzymes can also be RNA molecules called ribozymes, but the majority of enzymes are proteins.

Key Details

• Enzymes are proteins composed of amino acid sequences that determine their specific 3D structure and active sites, where substrate molecules bind to facilitate chemical reactions.
• They catalyze various biological reactions and are essential for metabolism.
• A few enzymes exist as RNA molecules (ribozymes), but no enzymes are lipid molecules.

This classification aligns enzymes mainly as protein biomolecules with catalytic functions in biological systems.