Are enzymes reactants explain your answer

A substance that speeds up a chemical reaction-without being a reactant-is called a catalyst. The catalysts for biochemical reactions that happen in living organisms are called enzymes. Enzymes are usually proteins, though some ribonucleic acid (RNA) molecules act as enzymes too.

Enzymes bind with chemical reactants called substrates. There may be one or more substrates for each type of enzyme, depending on the particular chemical reaction ... Since enzymes are proteins, this site is composed of a unique combination of amino acid residues (side chains or R groups)