INSTITUTE FOR
EXCELLENCE IN HIGHER
EDUCATION BHOPAL
Session:-2022-23
Biochemistry Assignment
Directed By:- Dr.Surbhi garde
Submitted By:-Namita ughade
Roll No:-420101

This is to certify that Namita ughade student of
Institute for excellence in higher education
Bhopal has completed the assignment in
Enzymes and it’s classification towards the
partial fulfillment of Bsc chemistry Honours
degree as Prescribed by the institution.
The assignment is in record of authentic work
carried by her.
Professor signature
CERTIFICATE

I have taken efforts however,it would not have
been possible without the kind support and help
of my teacher and Institution.
I thank my god for providing me with everything
that this, required in completing this assignment.
I am highly indebted to my teacher Dr. Surbhi
Garde Ma’am for her guidance and constant
supervision.
I am very thankful to everyone who supported
me in this assignment.
Namita ughade
ACKNOWLEDGEMENT

Enzymes - Introduction
 Enzymes are biocatalysts present in cells that speed up
biochemical reactions without getting itself destroyed in
the reaction.
 All types of biochemical reactions in the cell require
enzymes.
 Enzymes are typically proteins.
 Certain types of RNAcan also serve as catalysts. These
RNAmolecules are called ribozymes and DNAzymes.

Institute for excellence
in higher education
Bhopal

Nomenclature and Classification of Enzymes
 Enzymes are classified according the report of a Nomenclature
Committee appointed by the International Union of Biochemistry.
 This enzyme commission assigned each enzyme a systematic name and
a code number, called enzyme commission (EC) number.
Common name
Systematic name
EC number
: Alcohol dehydrogenase
: Alcohol: NAD+ oxidoreductase
: EC 1.1.1.1

Nomenclature and Classification of
Enzymes
The code numbers, prefixed by EC, which are now widely in use,
contain four elements separated by points, with the following
meaning:
(i) the first number shows to which of the six main classes the enzyme
belongs,
(ii) the second figure indicates the subclass,
(iii) the third figure gives the sub-subclass,
(iv)the fourth figure is the serial number of the enzyme in its sub-
subclass.

Nomenclature and Classification of Enzymes
 Example: EC 1.1.1.1 refers to the enzyme alcohol dehydrogenase (common
name).
 Its systematic name is alcohol : NAD+ oxido reductase.
 It catalyses the oxidation of alcohol to an aldehyde or ketone.
 Reaction: an alcohol + NAD+ an aldehyde or ketone + NADH + H+
 First digit 1 indicates the major class oxidoreductase
 Second digit 1 indicates the subclass acting on CH-OH group of donors
 Third digit 1 indicates the sub-subclass NAD+ as the electron acceptor
 Fourth digit 1 indicates the serial number of the enzyme alcohol
dehydrogenase

Enzyme - Classification
 Enzymes are classified into six categories (EC number classification)
by the International Union Of Biochemists (IUB) on the basis of the
types of reactions that they catalyze:
 EC 1 Oxidoreductases,
 EC 2 transferases,
 EC 3 hydrolases,
 EC 4 lyases,
 EC 5 ligases,
 EC 6 isomerases.

Classification of Enzymes
1. Oxidoreductases
Enzymes involved in oxidation-reduction reactions. Eg.Alcohol dehydrogenase
2. Transferases
Enzymes involved in transfer of groups from one molecule to another. Eg.
Hexokinase
3. Hydrolases
Enzymes that bring about hydrolysis by addition of water. Eg. Lipase
4. Lyases
Enzymes that catalyze the breaking of a chemical bond through means not
involving hydrolysis, and forms a double bond or adds a group to a double bond.
Eg. Fumarase
5. Isomerases
Enzymes involved in all kinds of isomerization reactions. Eg. Phosphohexose
isomerase
6. Ligases
Enzymes catalyzing the joining of two molecules with hydrolysis of ATP. Eg.
Glutamine synthetase

1. Oxidoreductases
 Oxidation-reduction (redox) reactions - hydrogen or oxygen atoms
or electrons are transferred between molecules.
 Example: dehydrogenases, oxidases, oxygenases and peroxidases
EC 1.1.1.1
Common name: alcohol dehydrogenase
Systematic name: alcohol:NAD+ oxidoreductase

2. Transferases
 These enzymes catalyse the transfer of a group between
substrates
 E.g: transfer of acyl, alkyl, amino, phosphate and
glycosyl.
 Involves transfer of amino group

3. Hydrolases
 These enzymes catalyze reactions that involve the process of
hydrolysis.
 They break single bonds by adding water.
 Some hydrolases function as digestive enzymes.
CH-O-CO-R2
CH2-O-CO-R1
CH2-O-CO-R3
+
CH2-O-CO-R1
CH-O-CO-R2
CH2-OH
Diacylglycerol
3
R -COOH
lipase
OH
Triacylglycerol
Fatty acid
H
Water

 Enzymes that catalyze the breaking of a chemical bond
through means not involving hydrolysis, and forms a double
bond or adds a group to a double bond.
 Eg: Fumarase
4. Lyases

 Enzymes involved in all kinds of isomerization reactions.
 Example: triosephosphate isomerase and phosphoglucose
isomerase
5. Isomerases

 Enzymes catalyzing the joining of two
hydrolysis ofATP. Eg. Pyruvate carboxylase
molecules with
6. Ligases

• Pineapple contains enzyme bromelain,
which can digest protein (proteolytic).
• Jell-O® is made of gelatin, a
processed version of a structural
protein called collagen found in many
animals, including humans.
• Collagen = big, fibrous molecule makes
skin, bones, and tendons both strong
and elastic.
• Gelatin you eat in Jell-O ® comes from
the collagen in cow or pig bones,
hooves, and connective tissues.
(Yummie!)
Meet the Enzyme: Bromelain

Meet the Enzyme: Catecholase
Lemon juice and other acids are used to preserve color
in fruit, particularly apples, by lowering the pH and
removing the copper (cofactor) necessary for the enzyme
to function.
Reaction:
catecholase
catechol + O2 ---------- polyphenol
colorless substrate brown product