ENZYMES

• Enzymes are proteins that accelerate chemical reactions.

• Substrates: The molecules present at the beginning of the reaction are called substrates.

• Enzymes convert substrates into different molecules, called products.

• Like all catalysts, enzymes work by lowering the activation energy for a reaction.

• Catalysts, like enzymes, act by lowering the energy difference between the reactants (A, B) and the transition state. This lowers the activation barrier for the reaction, allowing it to proceed more rapidly.

Nomenclature Of Enzymes

• Enzymes are usually named according to the reaction they carry out.

• Typically, the suffix ‘ase’ is added to the name of the substrate or the type of reaction (e.g. a polymerase or isomerase for a polymerization or isomerization reaction).

• Examples:

• Maltose-maltase

• Sucrose-sucrase

• Lactose-lactase

• Protein-protease

• Lipids-lipase

• Polymerization-polymerase

• Isomerization-isomerase

• The exceptions to this rule are some of the enzymes studied originally, such as pepsin, rennin and trypsin.

…

LIPIDS

• Lipids are a diverse group of compounds sharing the common property of being hydrophobic (soluble in non- polar solvents, insoluble in water).

• They are organic compounds, contains C, H, and O.

• Lipids include

Fatty acids,

Fats and oils,

Steroids (cholesterol, steroid hormones, bile salts)

Waxes,

Phospholipids

Terpenes, and

Tocopherols

Most of lipids are derivatives of fatty acids.

Types of lipids:

• Lipids with fatty acids

Fats and oils (triglycerides)

Phospholipids

Sphingolipids

Waxes

• Lipids without fatty acids

Steroids

Most of lipids are derivatives of fatty acids.

Lipids

Simple Lipids

Fats and Oils (Triglycerides)

Waxes

Compound Lipids

Phospholipids

Glycolipids

Derived Lipids

Steroids

Terpenes

Carotenoids

FATS and OILS

• Glycerol esters of fatty acids, which make up 99% of the lipids of plant and animal origin, have been traditionally called fats and oils.

• The main components of edible fats and oils are triglycerides (>95%). The minor components include mono- and diglycerides, free fatty acids, phosphatides, sterols, fat soluble vitamins, tocopherols, pigments, waxes, and fatty alcohols.

…

Introduction to Enzymology

• Functional Properties

• Nomenclature

• Enzyme specificity

• Enzyme regulation

Enzymes – Biological catalysts

• By definition a Catalyst :
– Accelerates the rate of chemical reactions
– Capable of performing multiple reactions (recycled)
– Final distribution of reactants and products governed by equilibrium properties

• Enzymes are biological catalysts
– Proteins, (a few RNA exceptions)
– Orders of magnitude faster than chemical catalysts
– Act under mild conditions (temperature and pressure)
– Highly Specific
– Tightly Regulated

Enzymes are critical for every aspect of cellular life

Enzyme Properties

• Vital for chemical reactions to occur in the cell (the breaking, forming and rearranging of bonds on a substrate (reactant) )

• Modified substrate (now a product) often performs a different task

• Consequence:
Transformation of energy and matter in the cell Cell-cell and intracellular communication Allows for cellular homeostasis to persist

…

Source: http://mutuslab.cs.uwindsor.ca/vacratsis/lecture2o8.pdf

ENZYMES

Submitted to:

Dr. Gul Shahnaz

Submitted by:

Group 1 A
Adeel Afzal
Fatima Saleh
Fatima Zahid
Maida Shafiq
Najia Hafeez

CONTENTS

Chemistry

Classification

Mechanism of Enzyme Action

Enzyme Kinetics

Inhibition

Activation

Specificity

CHEMISTRY

Introduction

Enzymes are biological catalysts that speed up the rate of the biochemical reaction.

Most enzymes are three dimensional globular proteins (tertiary and quaternary structure).

Some special RNA species also act as enzymes and are called Ribozymes e.g. hammerhead ribozyme.

STRUCTURE OF ENZYMES

The active site of an enzyme is the region that binds substrates, co-factors and prosthetic groups and contains residue that helps to hold the substrate.

Active sites generally occupy less than 5% of the total surface area of enzyme.

Active site has a specific shape due to tertiary structure of protein.

A change in the shape of protein affects the shape of active site and function of the enzyme.

…

What Is Enzyme Immobilization ?

Enzyme immobilization may be defined as a process of confining the enzyme molecules to a solid support over which a substrate is passed and converted to products.

What Is An Immobilized Enzyme?

An immobilized enzyme is one whose movement in space has been restricted either completely or to a small limited region.

Why Immobilize Enzymes?

Protection from degradation and deactivation.

Re-use of enzymes for many reaction cycles, lowering the total production cost of enzyme mediated reactions.

Ability to stop the reaction rapidly by removing the enzyme from the reaction solution.

Enhanced stability.

Easy separation of the enzyme from the product.

Product is not contaminated with the enzyme.

An Ideal Carrier Matrices For Enzyme Immobilization

Inert.

Physically strong and stable.

Cost effective.

Regenerable.

Reduction in product inhibition.

…