Question

Describe the catalytic cycle of an enzymatic reaction. Draw a diagram and explain.

Answer 1

A substrate that speeds up a chemical reaction without being a reactant is called catalyst and those involve in biological reaction that happen in living organism are called enzymes.To catalyse a reaction an enzyme will grab to one or more reactant molecules .These are called as substrates and the part of the enzyme where the substrates binds is called active site.It is the site where the catalytic action begins.Factors that affect the enzymatic reaction are temperature,pH etc.

There is one binding theory that states that binding of a substrate or someother molecule to an enzyme causes a change in the shape of the enzyme to enhances or inhibits its capacity.This theory is called induced - fit theory.

And another theory given by Emil Fischer is that enzymes have a specific shape that diectlt corelates to the shape of the substrate.Substrate fit into an enzyme as a key fits into a lock.So this theory is known as Lock and Key theory.

The catalytic cycle of an enzymatic reaction proceeds as follows:-

a) The substrate binds to the active site of the enzyme that marks the initiation of cycle.

b)The binding of the substrates induces a change in the shape of the enzyme molecule and the substrate tightly held itself into the active site.

c)The active site results in the breaking down of thechemical bonds of the substrate resulting in the formation of a new enzyme -product complex.

d)The enzyme molecule releases the product of the reaction and becomes free again to receive the new substraas a molecule .

The reaction can be showed as :-

E+S ---->ES ---->EP----->E + P

And the diagram is

This is the diagram for the catalytic cycle of an enzymatic reaction.

idriroga 600 15 20 - Enzyme available with empty active site I active site I substrate bindo to enzyme with indecced -substrate fit me onzy 6 Product is Meleased. ③ substrate is converted to product .