what are Enzymes I COMPLETE DETAIL BY INSTANT LEARNING

ENZYMES

Derived from a Greek word “yeast”.

Discovery:

It is discovered by a scientist named Kuhne in 1878.

They are the biological catalyst which speed up the chemical reactions or catalyze the chemical reaction.

Definition

The specialized protein which has the ability to act as a catalyst in a chemical reaction.

Nature of enzyme

All enzymes are protein in nature

They are very specific in their action

They are organic molecules while present per cell up to 2000-3000 in quantity.

Types

They may be extracellular enzyme or intracellular enzyme

Extracellular enzymes

They are trypsin or pepsin. They do not change after a reaction.

Intracellular enzymes

They change after a reaction.

Properties of a enzymes;

1)      Zymogene or pro-enzyme or pre-enzymes.

These are the inactive enzymes

They are activated by other enzymes or other substances.

For example

                 Pepsinogen                  ^{gastric HCl}                      pepsin

                 Tripsynogen         ^{enterokinase of pancreas}     trypsin.

2) Iso-enzymes;

Any enzyme which exist in multiple form in same organism, catalyst the same reaction.

For example

Lactose degudrogenase catalyses the reversible conversion of pyruvate to lactate.

They may be

LDH1 for heart

LDH2 for reticule endothelial system (breakdown of hemoglobin)

LDH3 for lungs

LDH4 for kidney and pancreas

LDH5 for muscles.

3) Location of enzymes

Enzymes not randomly found in the cells but present in the specific compartments.

For example

 In the liver cells, enzymes for glycolysis is present in cytoplasm..

For citric acid present in mitochondria.

4) Conduction and repression of enzymes

They may be

Constitutive enzymes or inducer or repressor enzymes.

Constitutive enzymes.

They are independent of adding any other substances.

Inducer or repressor enzymes.