Raman spectroscopy.pptx M Pharm, M Sc, Advanced Spectral Analysis
enzymes
1.
2.
3.
4. In 1833, a French
chemist Anselme
Payen discovered the
first enzyme, diastase.
In 1877, German
physiologist Wilhelm
Kuhne, first used the
term enzymes.
DISCOVERY OF ENZYMES
5. ENZYMES
Enzymes are biological catalysts, mainly proteins,
generated by an organism to speed up chemical
reactions.
They can be described as any of several complex
proteins that are produced by cells and act as catalysts
in specific biochemical reactions.
Biological catalysts are those catalysts which are found
in living organisms and they speed up the metabolic
reactions occurring in them.
6. CATALYSTS
A substance that lowers activation energy of a reaction
so the reaction occurs more quickly but, in the end, is
not used up by the reaction is called a catalyst.
7.
8. ACTIVATION ENERGY
To start any chemical reaction, energy is required. The
minimum amount of energy required to start a
reaction is known as it activation energy.
Activation Energy can be defined as the energy that
must be added to cause molecules to react with one
another.
9.
10. Nomenclature of enzymes
o An enzyme is named according to the name of the substrate it
catalyses.
o Some enzymes were named before a systematic way of naming enzyme
was formed.
Example: pepsin, trypsin and rennin
o By adding suffix -ase at the end of the name of the substrate,
enzymes are named.
o Enzyme for catalyzing the hydrolysis is termed as hydrolase.
Example :
maltose + water glucose + glucosemaltase
12. CHARACTERISTICS OF ENZYMES
1. Structure
Enzymes are globular complex protein structures
made up of long linear chains of amino acid ranging
from just 62 amino acid residues in size to over 2,500
residues.
Most enzymes are much larger than the substrates
they act on.
13. 2. Reactions
Unlike most catalysts enzymes are NOT consumed by the
reactions they catalyze.
During reactions only a small area is directly involved. This
area is called active site.
• It is the region where the substrate is recognized and then bound for the
reaction.
Active Site
• An enzyme substrate is the material upon which an enzyme acts.
Substrate
• A product is something "manufactured" by an enzyme from its
substrate.
Product
14. 3. Cofactors
There are some enzymes that need additional non
protein molecules/ions called cofactors. Cofactors can
be considered "helper molecules" that assist in
biochemical transformations.
Cofactor
Organic
Prosthetic Group:
tightly packed
Coenzyme: loosely
attached
Inorganic
15. 4. Metabolic Pathways
When enzymes work together metabolic pathways are
formed. In metabolic pathways a chain or path of
reactions is formed.
16. 5. Inhibitors
Inhibitors are molecules that decrease enzyme activity.
Many drugs and poisons are enzyme inhibitors.
17. Some types of inhibitors are given here:
Competitive :Substrate and inhibitor compete for the
enzyme.
Uncompetitive :The inhibitor cannot bind to the free
enzyme, only to the ES-complex.
Non-competitive : can bind to the enzyme at the binding
site at the same time as the substrate, but not to the active
site.
19. WHAT FACTORS AFFECT ENZYMES?
Enzymes are specific about the working conditions they
are provided.
Changes in the working conditions can change the type
of enzyme, its active site or its speed.
Some of the factors affecting enzyme activity are
discussed here:
1. Temperature
2. pH
3. Substrate Concentration
20. 1. Temperature
Every enzyme works at its best when given a specific
temperature. This temperature is called the optimum
temperature of that enzyme.
The optimum temperature of human enzyme is 37°C.
Reactions are accelerated when the temperature rises to
a certain limit .But when this limit is crossed
denaturation of enzymes takes place.
22. 2. pH
Optimum pH is the range of pH at which enzymes work
best.
A slight change in this optimum pH causes:
i).retardation in enzyme activity.
ii).blockage of enzymes.
iii).ionization of amino acids at the active sites.
23. pH affects the formation of hydrogen bonds and
sulphur bridges in proteins and so affects shape.
pepsin
trypsin arginase
2 4 8 106
pH
RateofReaction(M)
Acidic Basic
24. 3. Substrate Concentration
If enzyme molecules are available in a reaction,
increase in substrate concentration causes increase in
the rate of reaction.
If the ratio of enzymes is less than the ratio of
substrates then the enzymes enter a state called
saturation of active sites.
25. HOW ENZYMES REACT?
Lock and Key Model:
The enzyme and substrate are specific to each other. The
active site of an enzyme fits together with a substrate like
a lock and key. The key is the substrate and the lock is
the enzyme.
26. Induced Fit Model:
The enzyme is induced to undergo a slight alteration in
order to fit with the substrate perfectly.
27. SOME INDUSTRIAL APPLICATION
OF ENZYMES
Enzymes are produced in living organisms by cells but the
enzymes used for commercial purposes are synthetic and
made in industries.
Enzymes are used in:
1.Bread production.
2.Fermentation.
3. Paper production.
4.Production of cleaning products (detergent etc.)
28.
29. Some Enzymes And Their
Applications
APPLICATION ENZYMES USED
Food processing Amylase,Protease
Baby food Trypsin
Brewing industry Amylase,Protease
Fruit juices Cellulase,Pectinases
Dairy industry Lipases,Lactases
Paper industry Amylase,Ligninase, Xylanases,Cellulases
Biological detergent Amylase,Lipase,Cellulases
Rubber industry Catalase
Photographic industry Protease
32. Foundation of energy
Life force in all living things
Help in thinking, moving,
healing, reproducing,
growing etc…
Speed up all biochemical
reactions
Without enzymes, life won’t
exist.
IMPORTANCE OF ENZYMES IN OUR
LIVES
