Enzymes Flashcards
What is the function of enzymes, explain with reference to the enzymes impact of required energy.
An enzyme functions to reduce activation energy of a chemical reaction.
Lower activation energy means rate of chemical reaction increases due to less energy input required to begin the reaction.
What happens in the course of an enzyme catalysed reaction? Refer to: enzyme,, substrate, active site, enzyme-substrate complex and the product.
The substrate binds to the active site of the enzyme creating the enzyme-substrate complex.
Once in the enzyme-substrate complex, the substrate is converted to product.
The product is released from the enzyme allowing the enzyme to be reused in another chemical reaction.
Why is a different enzyme required for each different chemical reaction?
Hint: think about structure / shape of the enzyme and substrate.
The substrate must have a specific shape to fit into the active site of the enzyme (that catalyses the chemical reaction).
Only specific enzymes and substrates fir together, which means a different enzyme is required to catalyse each different chemical reaction.
Explain the induced fit model of enzyme action.
State if any structural changes are required in the enzyme.
In the induced fit model, the enzyme slightly changes the shape of its active site to accomodate the binding of a specific substrate in order to begin the chemical reaction.
Explain the lock-and-key model of enzyme action.
State if any structural changes are required in the enzyme.
shape of the enzyme’s active site is already complimentary to the substrate.
no structural changes are required in the enzyme
Where does a competitive inhibitor bind in order to prevent the substrate from binding to the enzyme’s active site?
Binds to the active site of the enzyme.
Has a complimentary shape to the active site.
Occupies the active site which prevents the substrate from binding.
Does the competitive inhibitor change the shape of the active site? If so, what affect does it have on the function of this enzyme?
Does not change the shape of the enzymes active site.
Blocks the active site by occupying it, which prevents chemical reaction.
Where does a non-competitive inhibitor bind in order to prevent the substrate from binding to the enzyme’s active site?
Binds to a regulatory binding site, which is separate from the active site.
Once bound to the regulatory binding site, the shape of the active site changes, preventing a substrate from binding to it.
Does the non-competitive inhibitor change the shape of the active site? If so, what affect does it have on the function of this enzyme?
Changes the shape of the active site by inducing conformational change within the protein.
Binds to the regulatory binding site.
Where does an uncompetitive inhibitor bind in order to prevent the substrate from binding to the enzyme’s active site?
Permanently binds to the enzyme’s active site via a covalent bond.
Does the uncompetitive inhibitor change the shape of the active site? If so, what affect does it have on the function of this enzyme?
The uncompetitive inhibitor changes the shape of active site by being permanently bound into part of the active site.
