2. Enzyme
substance produced by a
living organism which acts as
a catalyst to bring about a
specific biochemical reaction( reactions
that help sustain life and allow cells to grow.)
3. Termsrelatedto
Enzyme
Cofactor: A cofactor is a non-protein chemical compound or metallic
ion that is required for an enzyme's role as a catalyst. Cofactors can
be considered "helper molecules" that assist in biochemical
transformations
Prosthetic Group : if the non protein part is covalently bonded to
enzyme then it is called prostatic group
Coenzyme : if non protein part is loosely attached to enzyme
then it is termed as Coenzyme
4. Apoenzyme
&
Holoenzyme
Apoenzyme or apoprotein is an enzymatically inactive protein part
of an enzyme, which requires a cofactor for its activity
Holoenzyme is a complete, functional enzyme, which is
catalytically active
5. Characteristics
ofEnzyme
Enzymes are globular proteins
The increase the rate of reaction without being used up
Their presence does not affect the nature or properties
of end products
Amount of amount of enzyme can accelerate the
chemical reaction
Enzymes are highly specific
They are very sensitive to even minor change in pH ,
temperature,and substrate concentration
They lower activation energy
7. Mechanismsof
enzymeaction
An enzyme attracts substrates to its active site, catalyzes the chemical
reaction by which products are formed, and then allows the products
to dissociate (separate from the enzyme surface). The combination
formed by an enzyme and its substrates is called the enzyme–
substrate complex.
Enzyme + substrate •••• ES complex •••• Enzyme+ product
8. Enzymes
structure
Lock and key model
Lock-and-key model is a model for enzyme-substrate interaction
suggesting that the enzyme and the substrate possess specific
complementary geometric shapes that fit exactly into one another.
Enzymes are highly specific
. Induced Fit model
The induced-fit model states a substrate binds to an active site and
both change shape slightly, creating an ideal fit for catalysis