AAT Bioquest

What are the functions of coenzymes?

Posted July 1, 2022


Coenzymes are organic molecules that bind to active sites of certain enzymes and help in catalyzing reactions. Enzymes are essential proteins but are unable to function by themselves. They need coenzymes to function properly. Both enzymes and coenzymes are vital components in any biological system. These are some of the important functions of coenzymes: 

  • Producing recurrent energy

Energy production is one of the primary functions of coenzymes. The coenzyme ATP in particular plays a major role in moving energy within the cell and replenishing cellular energy. It releases energy constantly through the recurring process of hydrolysis. 

  • Preventing damage to DNA and cells

Many coenzymes have the ability to capture unbound electrons, thus preventing potential damage to DNA and cells. Unbound electrons are also known as free radicals. Free radicals in the body cause substantial damage to cells and DNA, sometimes even causing cell death. Coenzymes prevent this damage from happening by binding with the free radicals. The coenzyme CoQ10 deserves special mention in this regard. After a cardiac event, CoQ10 is used to help the heart tissue to heal faster by limiting free radical damage. 

  • Transferring groups of atoms during biological processes

Coenzymes play an integral role in transferring specific groups of atoms and molecules during several biological processes. One example is the coenzyme NADH, which plays a pivotal role in transferring hydrogen atoms from one part of a cell or organelle to another during a process called oxidative phosphorylation. During oxidative phosphorylation, NADH transfers four hydrogen atoms from one part of the mitochondria to another, which replenishes the cell’s ATP supplies.

  • Helping gain or lose electrons in redox reactions

Coenzymes facilitate redox reactions by helping molecules or atoms lose electrons during oxidation and gain electrons during reduction. One example of how coenzymes help redox reactions can be seen in oxidative phosphorylation, a process in which hydrogen atoms are transported. During this process, NADH donates two electrons to coenzyme Q. In losing the two electrons it becomes NAD+, entering an oxidized state and helping in the transportation of hydrogen atoms. 

Additional resources

Coenzymes and Their Role in the Evolution of Life

Amplite® Fluorimetric Coenzyme A Quantitation Kit *Green Fluorescence*

PhosphoWorks™ Luminometric ATP Assay Kit *Steady Glow*