Science 40

A catalyst is a substance that alters the rate of a chemical reaction without being used up or permanently changed chemically. Enzymes are catalytic proteins that help speed up chemical reactions in the body. A catalyst works by changing the energy pathway for a chemical reaction. It provides an alternative route (mechanism) that lowers the Activation Energy, meaning more particles now have the required energy needed to undergo a successful collision.

Figure 1 shows the energy of a reaction.

Increasing the concentration of enzyme in a chemical reaction will further increase the rate of that reaction. At some point, however, equilibrium is reached and the reaction plateaus as there is only so much material for the enzyme to interact with.