All About Enzymes (Most Important Facts)

Enzyme : 

Enzymes are proteins that act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. 

Substrates and products : 

The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. 

An enzymatic reaction in a living cell

First discovered enzyme: 

In 1833 Anselme Payen discovered the first enzyme Diastase, which is any one of a group of enzymes that catalyses the breakdown of starch into maltose.

Different parts of enzymes: 

The main two parts of enzymes are apoenzyme and cofactor. 

 1) Apoenzyme 

 Apoenzyme is the protein part of an enzyme. 

2) Cofactor 

A cofactor is the protein less part of the enzyme. 

I) Organic part of cofactors: 

I-a) Prosthetic group 

When the protein less part of the enzyme is tightly attached with protein then it is called a prosthetic group. 

I-b) Coenzyme 

When the protein less part of the enzyme is loosely attached to protein then it is called a coenzyme. 

II) Inorganic part of cofactors Such as metal ion's like Mg²+, Cu²+ e.t.c. 

 **Holoenzyme Apoenzyme and cofactor together called a holoenzyme. 

Three types of digestive enzymes: 

 

(1) Saccharolytic or amylolytic enzyme: Enzymes involved in the breaking down carbohydrates for energy. 

List of Amylolytic enzymes 

(2) Proteolytic enzyme: 

Enzymes are involved in the hydrolysis of proteins into peptides and amino acids; especially as part of the digestion of food. 

Lipolytic enzymes list 

(3) Lipolytic enzyme: 

Enzymes are involved in the breaking down of lipids or fats into fatty acids and glycerol. 

Lipolytic enzymes list

Proenzyme: 

Any inactive precursor of an enzyme is converted to an enzyme by proteolysis. 

Example: Pepsinogen and trypsinogen are inactive forms of proteolytic enzyme pepsin and trypsin 

Isoenzyme 

isozymes are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. 

For example, five isoenzymes of Lactic dehydrogenase are already discovered they are LD1, LD2, LD3, LD4 and LD5 

Antienzyme 

An inhibitor of enzyme action especially: one produced by living cells. 

Example: Tapeworms are made of protein and lived in our intestine but intestinal enzymes cannot digest them because tapeworms secrets a chemical that can prevent proteolytic enzymes work. 

Activator Enzyme 

activators are molecules that bind to enzymes and increase their activity. They are the opposite of enzyme inhibitors. 

Example: HCl, enteropeptidase, bile salts (sodium taurocholate and sodium glycolate) 

Ribozyme 

Ribozymes (ribonucleic acid enzymes) are RNA molecules that can catalyze specific biochemical reactions, including RNA splicing in gene expression, similar to the action of protein enzymes.