Cofactors

Definition

Cofactors are non-protein chemical compounds that assist enzymes in catalyzing reactions. They can be either inorganic ions or organic molecules (coenzymes) and are essential for the proper functioning of many enzymes.

5 Must Know Facts For Your Next Test

1. Cofactors can be divided into two categories: inorganic ions and organic coenzymes.
2. Many vitamins function as coenzymes or precursors to coenzymes.
3. Cofactors can bind to the active site of an enzyme or interact with the enzyme-substrate complex.
4. Without necessary cofactors, some enzymes are unable to perform their catalytic activity.
5. Metal ions like zinc, magnesium, and iron often act as cofactors for various enzymes.

Review Questions

• What are the two main categories of cofactors?
• How do vitamins relate to cofactors?
• Why are cofactors essential for enzyme function?

Related terms

enzyme: A protein that acts as a catalyst to speed up chemical reactions in biological systems

substrate: The specific reactant molecule upon which an enzyme acts

active site: The region on an enzyme where substrate molecules bind and undergo a chemical reaction