Almost all the chemical reactions that take place within cells are catalyzed by enzymes. Enzymes are biological catalytic proteins that lower the activation energy needed to start a chemical reaction and, as a result, greatly increase the rate of the reaction. The structure of an enzyme is based on the interaction and bonding of amino acids that make up the protein. There are thousands of different enzymes in a cell, and they are structurally diverse. The structure of the enzyme determines the chemical reaction that it will catalyze. How does DNA impact the function of enzymes?