112256
Enzymes
- Action of enzymes
- Biological catalysts
- They catalyse metabolic reaction. Active site
has a specific shape determined by the
tertiary structure.
- They can be
extracellular
or intracellular
- They catalyse metabolic reaction. Active site
has a specific shape determined by the
tertiary structure.
- Activation energy
- Enzymes reduce the activation energy by allowing
the reaction to occur at a lower temperature. This
speeds up the reaction. An ESC forms. The
enzyme reduces the repulsion of the molecules so
they can bonds more easily. The enzymes put
strain on the bonds so it break more easily
- Enzymes reduce the activation energy by allowing
the reaction to occur at a lower temperature. This
speeds up the reaction. An ESC forms. The
enzyme reduces the repulsion of the molecules so
they can bonds more easily. The enzymes put
strain on the bonds so it break more easily
- Models
- Lock and key changed
into the induced fit to
show that the ESC
changed shape slightly to
fit better
- Lock and key changed
into the induced fit to
show that the ESC
changed shape slightly to
fit better
- Biological catalysts
- Factors affecting enzymes
- Temperature: Higher temperature means
more kinetic energy and more successful
collisions resulting in more ESC. Too high
a temperature causes the enzymes to
denature as the bonds break
- pH: The H+ and OH- ions
disrupt the bonds in the
tertiary structure and denature
at high and low pH's
- Enzyme concentration: The more enzyme
molecules increases the ESC but a limited supply
of substrate results in to further effect
- Substrate concentration: The more substrate
there is the higher ESC. Until saturation where
all active sites are occupied when more
substrate has no further effect
- Substrate concentration: The more substrate
there is the higher ESC. Until saturation where
all active sites are occupied when more
substrate has no further effect
- Temperature: Higher temperature means
more kinetic energy and more successful
collisions resulting in more ESC. Too high
a temperature causes the enzymes to
denature as the bonds break
- Inhibition/cofactors
- Cofactors
- Coenzymes are small
organic non proteins
molecules, they take
part in the reaction but
are then recycled back
- Inorganic molecules are
in the enzyme and don't
take part in the reaction.
They help the substrate
and active bind
together.
- Inorganic molecules are
in the enzyme and don't
take part in the reaction.
They help the substrate
and active bind
together.
- Coenzymes are small
organic non proteins
molecules, they take
part in the reaction but
are then recycled back
- Competitive/Non competitive
- Competitive inhibitors have a similar shape to
the substrate and are complementary to the
active site. They compete with the substrate for
the active site and occupy it with no reaction.
- Non competitive inhibitors bind to the enzyme in
an alosteric site away from the active site.
Changes the shape of the active site so no more
substrate can bind to it.
- Non competitive inhibitors bind to the enzyme in
an alosteric site away from the active site.
Changes the shape of the active site so no more
substrate can bind to it.
- Competitive inhibitors have a similar shape to
the substrate and are complementary to the
active site. They compete with the substrate for
the active site and occupy it with no reaction.
- Poisons and drugs
- Cyanide: irreversible
inhibitor of cytochrome
c oxidase.
- Malonate inhibits succinate
dehydrogenase
- Arsenic inhibits
pyruvate
dehydrogenase
- Arsenic inhibits
pyruvate
dehydrogenase
- Malonate inhibits succinate
dehydrogenase
- Antiviral drugs and antibiotics.
- Cyanide: irreversible
inhibitor of cytochrome
c oxidase.
- Cofactors
Want to create your own Mind Maps for free with GoConqr? Learn more.