Difference Between Apoenzyme And Co-Enzyme

What Is Apoenzyme?

Apoenzyme is the protein component in which together with cofactor forms a complete enzyme. In other words, an enzyme that requires a cofactor but does not have one bound. An Apoenzyme is an inactive enzyme, activation of the enzyme occurs upon binding of an organic or inorganic cofactor.

Enzymes can speed up biochemical processes.  Some enzymes need cofactors (non-protein molecule) to carry out catalysis while others do not. Those that do not require cofactors are referred to as simple enzymes. Examples are pepsin, trypsin and urease. Those that require a particular cofactor are referred to as conjugate enzymes.

Conjugate enzymes are comprised of two main components, the cofactor, which is the non-protein part; and Apoenzyme, which the protein part. The cofactor may be an organic compound e.g  flavin or an inorganic compound e.g metal ion.  The organic cofactor may either be a coenzyme or a prosthetic group.

What You Need To Know About Apoenzyme

  1. Apoenzyme is a protein part of the holoenzyme or conjugate enzyme.
  2. It is large in size.
  3. An Apoenzyme is specific for an enzyme
  4. It takes part in only catalytic activity of the enzyme.
  5. Apoenzyme does not help in group transfer.
  6. Apoenzyme is thermolabile

What Is Co-Enzyme?

A coenzyme is an organic non-protein compound that binds with an enzyme to catalyze a reaction. Coenzymes are often broadly referred to as cofactors, but they are chemically different. A coenzyme cannot function alone, but can be reused several times when paired with an enzyme.

A coenzyme is a cofactor that is loosely bound to the enzyme and therefore may be released readily from the active site of the enzyme. Examples of coenzymes are those made of water-soluble vitamins (i.e B vitamins and vitamin C), and elements (e.g Cu, Ca, Zn, Mg, K, Ni, Co, Fe etc).

What You Need To Know About Co-Enzyme

  1. Coenzyme is the non-protein organic group which binds itself to the Apoenzyme to form holoenzyme or conjugate enzyme.
  2. It is small in size.
  3. A coenzyme can function as a cofactor for a number of enzymes carrying out that particular type of reaction.
  4. It helps in removing a product of chemical reaction besides bringing contact between the substrate and the enzyme.
  5. Coenzyme takes part in group transfer.
  6. Coenzyme is heat stable.

Also Read: Difference Between Enzymes And Coenzymes

Difference Between Apoenzyme And Coenzyme In Tabular Form

BASIS OF COMPARISON   APOENZYME COENZYME
Description Apoenzyme is a protein part of the holoenzyme or conjugate enzyme.   Coenzyme is the non-protein organic group which binds itself to the Apoenzyme to form holoenzyme or conjugate enzyme.  
Size It is large in size.   It is small in size.  
Specificity An Apoenzyme is specific for an enzyme   A coenzyme can function as a cofactor for a number of enzymes carrying out that particular type of reaction.  
Functionality It takes part in only catalytic activity of the enzyme.   It helps in removing a product of chemical reaction besides bringing contact between the substrate and the enzyme.  
Group Transfer Apoenzyme does not help in group transfer.   Coenzyme takes part in group transfer.  
Effect Of Heat Apoenzyme is thermolabile   Coenzyme is heat stable.  

Also Read: Difference Between Cofactor And Coenzyme