3. Cofactors are non
protein molecules
that assist enzyme
during that Catalysis
of reactions.
• Enzyme without
its cofactor is
referred to as
an apoenzyme
• The complete,
catalytically
active enzyme is
called
holoenzyme
5. Prosthetic group
• The organic compound which are tightly bind
the cofactors are called prosthetic group
• Loosely bound cofactors serve functions like
those of prosthetic group but bind in a
transient, disposable manner either to the
enzyme or to a substrate
• They are more likely substrate because they
bind to and are released from the enzyme
just as substrate and products are formed
6. Prosthetic group
• Tightly integrated into the
enzyme structure by covalent or
non covalent force
B) Inorganic
•Metal are the most common
prosthetic group
Metal ions :
Cobalt ,copper,Magnesium,
Manage, Zinc, iron
A) organic
• Flavin mononucleotide
• Flavin adenine
dinucleotide
• Biotin
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7. • Enzyme that contain tightly bound metal ion
are termed- metalloenzyme
• enzyme that require metal ion as loosely bound
cofactor are termed as metal activated enzyme
• Metal ion facilitate binding and orientation of
the substrate
• Formation of covalent bond with reaction
intermediates
• Interact with substrate to render them more
electrophilic and nucleophilic
Role of metal ions
8. • Coenzymes serve as a recyclable shuttles - or
group - transfer agent that transport many
substrates from their point of generation to
their point of utilisation.
• Nicotinamide is a component of the redox
coenzyme NAD and NADP
• Riboflavin is a component of the redox
coenzyme FMN and FAD
• Thiamin participate in decarboxylation of α-
ketogluteric acids and folic acid
Coenzymes
9. • Hydrogen atom or hydride ions
• Methyl group
• Acyl group
• Oligosaccharide
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Chemical materials transported by coenzyme include