Role of Enzymes in Chemical Reactions

By Liz Veloz; Updated April 24, 2017
Enzymes are critical for cell functioning.

Enzymes are proteins that regulate chemical reactions but are themselves unchanged by the reaction. Because they’re often required to start or speed up a reaction, enzymes also are called catalysts. Without enzymes, many biochemical reactions would be energetically inefficient.

Function

Enzymes form temporary bonds with one or more of the reactants, or substances that are transformed during the reaction, to make the products of the reaction. These bonds reduce the amount of energy needed to begin the reaction, which speeds up the process.

Features

Names for enzymes usually end in the suffix “-ase,” making enzymes easy to distinguish. For example, an enzyme responsible for removing a phosphate group from a molecule is called a phosphatase, and an enzyme responsible for breaking down proteins is called an protease.

Types

The International Union of Biochemistry recognizes about 300 different types of enzymes. Specific enzymes are involved in making chemical energy for cells, breaking down proteins or nucleic acids or catalyzing oxidation-reduction reactions.

Significance

Without enzymes, the energy stored in molecules might be all but inaccessible to cells. Just as wood doesn’t spontaneously catch fire, breaking chemical bonds to release energy requires an investment of energy.

Effects

Just as applying heat starts the burning process, enzymes allow chemical reactions to proceed by lowering the amount of energy required to run the reaction so the cell can function efficiently.

About the Author

Liz Veloz is a writer, scientist and college teacher living in Madison, Wis. Her science, travel and adventure writing has appeared in numerous literary journals and other publications. Veloz holds a doctorate in the biological sciences and a Master of Arts in English from the University of California, Davis.