Difference between Cofactor and Coenzyme

Cofactor and Coenzyme are essential non-protein molecules for an enzyme. Difference between Cofactor and Coenzyme is described step by step.

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Definition of Cofactor and Coenzyme

Cofactors are either one or more inorganic (e.g. metal ions, iron-sulfur clusters) or complex organic or metalloorganic (e.g. flavin and heme), non-protein chemical compounds that assist in the biochemical transformation of an Apoenzyme.

On the other hand, Coenzymes are small, organic or metalloorganic, non-protein molecules that are as auxiliary for the specific action of an enzyme.

Classification of Cofactor and Coenzyme

Cofactors are divided into two broad groups:

Organic cofactors, such as flavin or heme,
Inorganic cofactors, such as metal ions (Mg²⁺, Cu²⁺, Mn²⁺), or iron-sulfur clusters.

Coenzymes are divided into two categories:

Cosubstrates: They are temporarily bound to the protein and will be released at some point, then get back in.
Prosthetic groups: They are bound permanently to the protein.

Chemical nature of Cofactor and Coenzyme

Cofactors are non-protein, metallic ions. They may be either inorganic ions or organic molecules. Additionally, some sources also limit the use of the term “cofactor” to inorganic substances.

On the other hand, Coenzymes are complex organic or metalloorganic, non-protein chemical compounds.

Function of Cofactor and Coenzyme

Cofactors also are known as “helper molecules” that assist apoenzyme during the catalysis of reactions.

While Coenzymes act as a transient carrier of specific functional groups from enzyme to enzyme. Coenzymes bind to the apoenzyme and assist in enzyme activity.

Example of Cofactor and Coenzyme

Cofactors: metal ions Mg²⁺, Cu²⁺, Mn²⁺, or iron-sulfur clusters.

Coenzyme: Biotin, Coenzyme A, NADH, NADPH and adenosine triphosphate (ATP), Riboflavin, Thiamine, and Folic Acid etc.

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Summary of the difference between Cofactor and Coenzyme

Features	Coenzyme	Cofactor
Definition	Co-enzymes are small, organic or metalloorganic, non-protein molecules that are as auxiliary for the specific action of an enzyme.	Co-factors are either one or more inorganic (e.g. metal ions and iron-sulfur clusters) or a complex organic or metalloorganic (e.g. flavin and heme), non-protein chemical compounds that assist in the biochemical transformation of an Apoenzyme.
Classification	Co-enzymes are divided into two categories: 1. Co-substrates: They are temporarily bound to the protein and will be released at some point, then get back in. 2. Prosthetic groups: They are bound permanently to the protein.	Co-factors are divided into two broad groups: 1. Organic cofactors 2. Inorganic cofactors Organic co-factors are sometimes further divided into co-enzymes and prosthetic groups.
Chemical nature	Co-enzymes are complex organic or metalloorganic ,non-protein chemical compounds.	Co-factors are non-protein, metallic ions. They may be either inorganic ions or organic molecules. Additionally, some sources also limit the use of the term “co-factor” to inorganic substances.
Function	They act as a transient carrier of specific functional groups from enzyme to enzyme. Co-enzymes bind to the apoenzyme and assist in enzyme activity.	Co-factors also are known as “helper molecules” that assist apoenzyme during the catalysis of reactions.
Another name	Transient carrier molecule	Helper molecule
Example	Biotin, Co-enzyme A, NADH, NADPH and adenosine triphosphate (ATP), Riboflavin, Thiamine, and Folic Acid.	Metal ions such as Mg2+, Cu2+, Mn2+, or iron-sulfur clusters.