Atomic and Molecular Structure

Coenzymes – What is Role of Coenzymes?


Coenzyme plays a role in the functioning of cells. Reactions within the cells work to break down the nutrients. And combine molecules for cellular activities that keep the cells alive. Enzymes accelerate these reactions.

Without enzymes, these reactions may not happen. Coenzyme, in turn, supports the actions of enzymes. They lightly bind to enzymes to help them complete their functions. Coenzymes are non-protein, organic molecules. Which facilitate the catalysis, or reaction, of its enzyme.


Definition of Coenzyme

A coenzyme is an organic non-protein compound. which binds with an enzyme to catalyze a reaction. Coenzymes are often mostly called cofactors; however, they are chemically different. A coenzyme cannot function singly but can be reused numerous times when it is paired with an enzyme.

Types of Enzymes

Cofactors are molecules that combine to an enzyme during chemical reactions. Commonly, all compounds that help enzymes are cofactors. But, cofactors are divided into these three subgroups:

  1. Coenzymes

These are reusable non-protein molecules which have carbon (organic). They bind lightly to an enzyme at the active site to help catalyze reactions. Maximum are vitamins, vitamin derivatives, or form from nucleotides.

  1. Cofactors

Unlike coenzymes, proper cofactors are reusable non-protein molecules. That do not have carbon (inorganic). Generally, cofactors are metal ions such as iron, zinc, cobalt, and copper

  1. Prosthetic Groups

These can be organic vitamins, lipids, sugar, or inorganic metal ions. Though, unlike coenzymes or cofactors, these groups combined very tightly or covalently to an enzyme to aid in catalyzing reactions.

Role of Coenzymes

Enzymes are necessary proteins responsible for a multitude of reactions in organisms. Though, they do not work by themselves. They are an important part of any biological system.

Some important roles of it are as follows:

  1. Energy Production

One primary role of coenzymes is to help with the production of energy. Especially, the coenzyme ATP is a chief player in moving energy within the cell. ATP’s structure has three phosphate groups. When the last one is cleaved off all through a process known as hydrolysis.

Energy comes out. ATP is regularly recycled, picking up more phosphate groups. That is then broken off once again, refilling cellular energy.

  1. Transferring Groups

Coenzymes also help in transferring definite groups of atoms from one molecule to another. Such as hydrogen transfer, the activity of hydrogen atoms from one part of a cell or organelle to another. It is essential to many processes, containing the reproduction of ATP molecules.

The coenzyme NADH in specific is significant in this procedure. When a process called oxidative phosphorylation starts in a cell. The coenzyme NADH transferences four hydrogen atoms from one part of the mitochondria to the next.

  1. Redox Reactions

Another primary role of coenzymes is to help in the loss or gain of electrons in redox reactions. For the period of oxidation, a molecule or atom loses electrons. Reduction happens when a molecule or atom gains electrons.

Oxidative phosphorylation is also a good example of redox. And also an illustration of how coenzymes work in tandem. So the coenzyme donates two electrons to coenzyme Q. NADH. Then it becomes NAD+, entering an oxidized state because it has lost electrons.

  1. Antioxidants

As many coenzymes are capable to capture electrons. They often function as antioxidants. These Unbound electrons, also known as free radicals. It can harm cells, damaging DNA and even leading to cell death. Antioxidants are able to bind free radicals.

It prevents such damage from happening. Some coenzymes, such as CoQ10, are even used as medical interventions. After a cardiac occurrence like a heart attack or heart failure, CoQ10 can be useful to limit free radical damage during the tissue of the heart is healing.

Examples of Coenzymes

Maximum organisms cannot produce coenzymes naturally. In its place, they are introduced to an organism in two ways. Many coenzymes are vitamins or derived from vitamins. If vitamin intake is too low, then an organism will not have the coenzymes required to catalyze reactions.

Water-soluble vitamins, that contain all B complex vitamins and vitamin C. It leads to the production of coenzymes. Two of the most essential and prevalent vitamin-derived coenzymes are nicotinamide adenine dinucleotide (NAD) and coenzyme A.

Non-vitamin coenzymes naturally help in chemical transfer for enzymes. They ensure physiological role, like blood clotting and metabolism, happen in an organism.

Solved Question for You

Q: Compare coenzymes with enzymes.

Ans: Coenzyme is a substance that enriches the action of an enzyme. An enzyme is a protein that works as a catalyst to facilitate and speed a chemical reaction. Coenzymes are very small molecules. They cannot alone catalyze a reaction. But they can help enzymes to do so.

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