Enzymes Structural & Functional Organization Of Cell & Functions. Enzymes in medicines. Isoenzymes & organ specific enzymes

1. NAME : HAMENT SHARMA
GROUP : 239
TOPIC : Enzymes Structural & Functional
Organization Of Cell & Functions. Enzymes in
medicines. Isoenzymes & organ specific enzymes
CHECKED BY : MADAM RAUZA

2. • Enzymes are biological
catalysts.
Enzymes can be defined as the reaction catalysts of
biological systems or biological catalysts they
are produced by living cells and are capable of
specific products. The set of enzymes in each
cell is genetically determined.
• By nature enzymes are proteins (4 types of str.)
• (primary
• secondary
• tertiary
• quaternary structure)

3. • High effect
• All enzymes are proteins by nature, have all properties
of proteins
• Enzymes are more specific than inorganical catalysts in
their action
• Enzymes are more efficient than inorganical catalysts
• Enzymes are specific in their action. ( absolute (S-E), (S-
E1,E2.E3) relative, stereospecificitiy(S- L form, D- form -
E))
• After reaction they never change. After reaction they are
liberated
• They act at normal temperature (37), at normal pressure,
PH and in water medium

4. Enzymes-
Proteins
Simple
Complex
protein part
(apoenzyme)
non protein part
(coenzyme, cofactors)
inorganical
ions of metalls
organical
substances
Aromatic, aliphatic,
heterocyclic,
nucleotides (Vitamins)

5. Significance of vitamins as cofactors
Signs or
Symptoms
metabolism
Metabolic
processes
Vitamins
(N)
cofactors ENZYMES
catalysts of biochemical reactions

6. Structure of enzymes.
An enzyme-substrate complex forms when
the enzyme’s active site binds with the
substrate like a key fitting a lock.
The shape of the enzyme must match the shape of the
substrate. Enzymes are therefore very specific; they
will only function correctly if the shape of the
substrate matches the active site.

8. On the level of tertiary structure
enzyme has also another site. The
enzymes also possess other site
which is called allosteric site. The
reagents which have bind to the
allosteric site one called effectors
(also called modifiers and
modulators). The allosteric
activators or inhibitors. Another
name of this site is regulatory site.

9. • The mechanism of enzymes reaction.
This binding takes place between the substrate molecule and
a place over the enzyme called substrate site or the active
site. The active site has a high affinity and great specificity
for the substrate molecule. In certain cases the active site of
the enzyme is complementary to the substrate, so that
enzyme and substrate recognize each other; this is the lock
and key theory of enzyme action.
• The stages of enzymes action.
• Formation of enzyme – substrate complex enzyme
+substrate->enzyme substrate complex or E + S -> ES. The
linkages between the enzyme and the substrate by non
covalent bonds including H bonds, electrostatic bonds; thus
every wear bonds takes place between the S molecule and a
place over the enzyme called the substrate site or the active
site.
• Conversion of the substrate to the product forming E-P
[product] – E –S -> E-P
• Release of the product from the enzyme – E – P -> E+P.
• E-enzyme; S-substrate.

11. Classification of enzymes. (By type of chemical reaction)
• 1. Oxidoreductases are catalize oxidation - reduction reactions are
transport of atom of H ( hydrogen ) and electrons.
e e
A + B + B+ A
May be aerobic dehydrogenase for transport of hydrogen
FMN,FAD Vit. B2 COENZYMES
May be anaerobic dehydrogenase with coenzymes such as
NAD AND NADP Vit. PP
• 2.Transferases- facilitate transfer of groups from one substrate to another
A(X)+ B A+ B (X)
• 3.Hydrolases - catalyse hydrolysis
AB+H2O AH +BOH
• 4.Lyases – catalyze removal of groups and usually leave double bonds.
AB A+B
• 5.Isomerases catalyse conversion to other isometric forms
A A”
• 6.Ligases catalyse linking together of two compounds at presence of
energy ATP ATP
• A+B AB+ADP+H3PO4 or AMP + H4P2O7

12. According to the presently accepted
international system of classification enzymes
have been divided into sub- classes and each
sub-class into a number of sub-sub classes. This
systematic classification helps assigning code
number to enzymes. The full code number for
an enzyme consists of four digits. The first
stands for class, the second digit for the
subclass, the third for the sub-sub class and the
fourth one in the sub-sub subclass. In naming an
enzyme the first part of the enzyme indicates the
substrate and the second part consists of word
ending in ase and indicating the type of reaction.
The names of enzyme in many cases and in ase
which is presided by their names are trivial and
do not at all point out their substrate e.g.
pepsin, trypsin

13. • Regulation of enzymes activity
The activity of enzymes depends on:
• Quantity of enzymes in the cell and localization.
• From of change in PH and temperature, pressure,
concentration of substrates.
• From of presence of allosteric effectors and activators or
inhibitors. Allosteric regulation reversible and
irreversible.
• Chemical modification of enzymes. Enzymes regulated by
covalent linkages – several enzymes present in at inactive
form. They become activated when phosphate bonds are
added to their molecules forming covalent bonds with the
enzymes. This process occurs as result chemical reaction-
phosphorylation. ( and another chem. reactions)

14. Proenzyme + ATP enzyme.OPO3H2
+ ADP
(Inactive form) (active form)
Dephosphorylation:
enzyme.OPO3H2
+
H2O Proenzyme +H3PO4

15. • Reversible inhibition may be competitive and non
competitive type.
• 1. competitive inhibition – competitive inhibitors
bear structural resemblance to the substrate and
bind at the active site but fail to undergo the
reaction. These thus compete with the substrate for
the active site. Addition of more substrate will
overcome the inhibition.
Succinic acid, malonic acid
Malonate is competitive inhibitor for succinate.

16. 2 Non-competitive inhibition – In this case, there is no
structural resemblance between the inhibitor and
the enzyme substrate. The inhibitor does not
combine with the enzymes at active site but
combines at some other site such inhibitor can
combine with free enzyme as well as with the
enzyme bound to its substrate – E-S complex.
The antibacterial effect of sulfonamides e. g.
sulfanilamides are also explained by their close
resemblance to para-amino-benzoic acid (PABA)
which is a part of the molecule of folic acid, an
essential normal constituent of bacterial cells.
The sulfonamides inhibit the formation of acid
(PABA) by bacterial cells and thus the bacterial
growth is stopped.

17. • 1. Enzymes substitution in digestive disturbance.
• 2. Pepsin and pancreatic ( containing enzymes of pancreatic
juice )alone or along with dry powder are the most
frequently used enzyme preparations in digestive
disorders.
• 3. Blood coagulation – Thrombin is used in locally to stop
bleeding.
• 4. Locally applied enzyme preparations hyaluronidase is
used in the treatment of sprains, hematomas and
thrombphlebitis. Trypsin and chymotrypsin these are
used to degrade necrotic tissue, masses of pus, sections
and effusions thus and accelerating wound
conditions. RNA- ase and DNA- ase – these are used
in the form of sterptodornase for the disintegration of pus
Enzymes for cancer treatment L- asparagines has
proved very useful un the therapy of lymphoblast
leukemia especially in children.

18. • 5. Enzymes for thrombolysis. Streptokinase is beign widely to
minimize cases of coronary thrombosis to minimize the extent of
mycordial infraction by dissolving the thrombin. The increased
activity of the plasma fibrinolysis can dissolve the fibrin
clots . Streptokinase and urokinase greatly activate the
fibrinolysis system.
• 6. Immobilized enzymes. The enzymes which covalently
connected to organically or inorganically polymeric carrier are
called immobilized enzymes. They are found in specific
microcapsules. Immobilized enzymes possess by specific action,
by stability. They are stabilized enzymes. They are used for of
treatment diseases chronic glomerulonephritis chronic
pylonephritis. They are used for of hemodialysis artificial
kidney or hemodialyzer.
• Diagnostic value of serum enzyme levels:

19. • The determination of enzymes in the serum is of great help in the diagnosis
of certain diseases.
– Amylase – in is increased in parotitis and acute pancreatitis.
– Cholinesterase – actually pseudo cholinesterase. It is decreased in liver
disease, and raised in nephritic syndrome.
– Alkaline phosphates it is raised in rickets, hyperparathyroidism. Paget’s
disease, osteoblastic sarcoma and obstructive jaundice
– serum glutamic oxaloacetic transaminase it is raised in acute myocardial
infraction. SGOT is found in a high concentration with in the cardiac muscle
fibers leaks into the blood stream on injury to the fibers. It is also raised in
acute liver damage.
– Serum glutamic pyruvic transaminase it is raised in acute liver damage. On
injury to liver cells, this enzyme leaks into the blood stream.
– Lactic dehydrogenase or LDH – it is raised in acute myocardial
infraction it is also raised in acute liver damage. Its isoenzymes can also
be measured which gibe more specific information.
– Creatine phosphokinase or CPK it is raised in diseases of the muscle and
in myocardial infraction.

20. NADH2
CH3 CH3
| NAD |
CHOH C=O
| LDH |
COOH COOH
LACTATE PYRUVATE

21. Lactatedehydrogenase or LDH (4
SUBUNITS H type and M types)
LDH1-heartmuscle(H4)
LDH2-heartmuscle(HM3)
LDH3 many tissues(H2M2)
LDH4-liver (M3H)
LDH5 –liver (M4)
H H
M M