The document discusses the active sites of enzymes, emphasizing their features, structure, and role in substrate binding. It explains that active sites are three-dimensional clefts formed from various amino acids that facilitate chemical reactions by binding substrates through weak attractions. The document also outlines models of enzyme active sites and the properties influencing substrate binding and catalysis.

1. Active sites of enzyme
BY
AVINASH TIWARI
M. TECH, BIOTECHNOLOGY
2ND YEAR (3RD SEM.)
201710902010002

2. CONTENT
 Introduction
 Feature of the active site
 Structure
 Binding site
 Models for active site of enzyme
 Properties that Affect Binding
 Mechanism of catalytic site

3. INTRODUCTION
 Active sites of enzyme is
that point where, substrate
molecule bind for the
chemical reaction
 It is generally found on the
surface of enzyme and in
some enzyme it is a “Pit”
like structure
Active site

4. Feature of the active site
 The active site is a three-dimensional cleft formed by groups
that come from different parts of the amino acid sequence
 The active site takes up a relatively small part of the total
volume of an enzyme
 Active sites are clefts or crevices
 Substrates are bound to enzymes by multiple weak attractions.
 The specificity of binding depends on the precisely defined
arrangement of atoms in an active site.

5. STRUCTURE OF ENZYME
Enzyme (protein)
Scaffold-to
support
and
position
active site
Binding
site- bind
and orient
substrate(s)
Catalytic
site-reduce
chemical
activation
energy

6. Binding site
 Form the 4 type of bond with substrate
1. Electrostatic bond
2. Hydrogen bond
3. Van Der Waals forces
4. Non- covalent bond

7. Models for active site of enzyme
 Lock and key theory  Induced fit model

8. Properties that Affect Binding
 Complementarity
 Flexibility
 Surfaces
 Non-Covalent Forces
 Affinity

9. MECHANISM CATALYTIC SITE