A Level Biology Practice Exam

What role do cofactors play in enzymatic reactions?

1. They are the main structural components of enzymes

2. They are non-protein components necessary for enzyme function

3. They act as competitive inhibitors

4. They assist in the synthesis of nucleic acids

The correct answer is: They are non-protein components necessary for enzyme function

Cofactors play a critical role in enzymatic reactions by acting as non-protein components that are necessary for the proper functioning of enzymes. These molecules can be metal ions, like magnesium or zinc, or organic molecules known as coenzymes, such as vitamins. They contribute to the enzyme's ability to catalyze reactions by participating in the chemical processes or assisting in stabilizing the enzyme-substrate complex. Without these cofactors, many enzymes would not be able to perform their catalytic functions effectively, which could lead to metabolic issues in biological systems. Essentially, cofactors enable enzymes to perform their roles in facilitating biochemical reactions, making them indispensable for numerous physiological processes.