Living system controls its activity through enzymes. Enzymes are biological catalysts. They increase
or decrease the rate of chemical reaction in the cell, but enzymes remain unchanged after the reaction. Most cellular reaction occurs about a million time faster with the help of the enzymes rather than in the absence of it. Enzymes work on which chemical
substances are known as substrate. Enzyme works on substrate to form an enzyme-substrate complex. After reaction, this complex split and produce the
Product and enzyme get released. In the end of the reaction, enzyme remains unchanged and paired with another substrate. A small amunt of enzyme can work on a huge amount of substrate.
The term, enzyme was first used by Kuhne(1878). Buchner (1897) first collected enzymes from Yeast
The general properties of enzymes are
All enzymes are globular protein and catalyst.
Their presence do not affect on characteristic and type of the Product.
Enzyme reactions are bi-directional.
Enzymes are selective for their substrate.
Enzyme’s activity can be influenced by other molecules. Inhibitors are the molecule that decreases enzyme’s activity. Activators are molecule that increases
Enzyme works in definite pH, temperature and concentration.
The protein parts of the enzymes are apoenzyme, and non-protein part is known as co-factors.
International Union of Biochemistry (IUB) and Enzyme Commissiob (EC) classify and name the various
enzymes. Generally, -ase is added with the name of the substrate to form the name of an enzyme, eg; the enzymes function on arginine and urea are respectively known as arginase and urease.