Presented by
KASHIF HAIDER
BMLT 5th semester
 Enzyme are classified into six functional classes (EC
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number classification ) by the international union of
biochemists(I.U.B) on the basis of the type of reaction
that they catalyze
EC 1. Oxidoreductases
EC 2. Transferases
EC 3. Hydrolases
EC 4. Lyases
EC 5. Isomerases
EC 6. Ligases
 Each enzyme has classification number
consisting of four digits:
Example, EC (2.7.1.1) HEXOKINASE
 EC: (2.7.1.1) these components indicate the following groups
of enzymes:
 2. IS CLASS(TRANSFERASE)
 7. IS SUBCLASS(TRANSFER OF PHOSPHATE)
 1. IS SUB-SUB CLASS(ALCOHOL IS PHOSPHATE
ACCEPTER)
 1. SPECIFIC NAME
Class
General reaction
catalyzed
Typical
subclasses
function
1. Oxidoreductases
Oxidationreduction reaction
Oxidases
Reductases
Dehydrogenases
Oxidation
Reduction
Remove 2H to from
double bond
2. Transferases
Transfer of amine
group
Transaminases
Kinases
Transfer amino group
Transfer phosphate
group
3. Hydrolases
Hydrolysis reaction
Peptidases
Hydrolyze peptide bond
Lipases
Hydrolyze ester bond in
lipid
Hydrolyze 1,4-glycosidic
bond in amylase
Amylases
4. Lyases
Addition of a group
to a double bond or
removal of a group
from a double bond
without hydrolysis or
oxidation
Decarboxylases
Dehydrases
Deaminases
5. Isomerases
Rearrangement of atom Isomerases
to form isomer
Epimerases
Convert sis and
trans
Convert D and L
isomer
6. Ligases
Bonding of molecules
using ATP energy
Combine molecules
Add CO2
Synthatases
Carboxylases
Remove CO2
Remove H2O
Remove NH3
 - Biochemical activity:
 Catalyse Oxidation/Reduction reaction act on many
chemical grouping to add or remove hydrogen atom.
 Example:
-Lactate dehydrogenase.
-Glucose oxidase.
-Peroxidase.
-Catalase.
-Phenylalanine hydroxylase.
 Biochemical activity:
- Transfer a functional group (e.g. methyl or phosphate)
between donor and acceptor molecules.
Example:
- Transaminases(ALT & AST).
- Phosphotransferase (Kinases).
- Transmethylases.
- Transpeptidases.
- Transacylases.
 Biochemical activity:
= Catalyse the hydrolysis of various bonds add water
across a bond.
Example:
- Protein hydrolyzing enzymes (peptidases).
- Carbohydrases ( Amylase, Maltase, lactase).
- Lipid hydrolyzing enzyme (lipase).
- Deaminases.
- Phosphatases.
 Biochemical activity:
= Cleave various bond by mean other than hydrolysis
and oxidation.
= Add water, ammonia or carbon dioxide across double
bond, or remove these elements to produce double
binds.
Example:
 Fumarase.
 Carbonic anhydrase.
 Biochemical activity:
= Catalyse isomerization changes within a single
molecule.
= Carry out many kind of isomerization:
o
L to D isomerization.
o
Mutase reactions ( Shifts of chemical groups).
Example:
- Isomerase.
- Mutase.
 Biochemical activity:
= Join two molecules with covalent bond catalyse
reactions in which two chemical groups are joined (or
ligated) with the use of energy from ATP.
Example:
- Acetyl CoA Carboxylase.
- Glutamine synthatase
 Enzyme in the circulation are divided into two group:
 1> Plasma functional
 2> Plasma non fuctional
 Certain enzyme are normally present in the plasma
and they have specific function to perform. These
enzyme activities are higher in plasma than in the
tissue. They are mostly synthesized in the liver and
enter the circulation.
Impairment in the liver function or genetic
disorder often lead to a fall in the activities of plasma
function enzyme.
 These enzyme are either totally absent or present at a
low concentration in plasma composed to their level
found in the tissue.
Estimation of the activities of non plasma specific
enzyme is very important for the diagnosis and
prognosis of several diseases.
Enzyme
Reference value
Disease in which increase
Amylase
80-180 smogi
unite/dl
Acute pancreatitis , mumps(acute
paratitis)
Lipase
0.2-1.5IU/L
Acute pancreatitis, increase
carcinoma of pancreas
ALT/SGPT
3-40 IU/L
Jaundice , cirrhosis of liver , acute
hepatitis
AST/SGOT
4-45 IU/L
Myocardial infarction , liver disease
, live cancer
Alkaline phosphate 3-13 KA Unite/ dl
Bone disease rickets ,
hyperthyroidism
ACP
0.5-4 KA Unite /dl
Infective hepatitis , prostatic cancer
LDH
50-200 IU/L
Myocardial infarction , leukemia ,
muscular dystrophy
Creatinine kinase
10 -50 IU/L
Myocardial infarction , muscular
dystrophy
Aldose
2-6 IU/L
Muscular dystrophy , liver disease ,
myocardial infarction
5’ Nucleotidase
2-15 IU/L
Hepatitis , tumor obstructive
jaundice
GGT
5-40 IU/L
Alcoholism , infective obstructive
jaundice