Final answer:
A noncompetitive inhibitor can bind to either the free enzyme or the enzyme-substrate complex, altering the configuration of the active site. It blocks substrate binding to the active site by inducing a conformational change. The Michaelis-Menten equation has limitations and a Lineweaver-Burk plot can be used to overcome them.
Step-by-step explanation:
A noncompetitive inhibitor can be bound to either the free enzyme or the enzyme-substrate complex because its binding site on the enzyme is distinct from the active site.
The binding of this kind of inhibitor alters the three-dimensional conformation of the enzyme, changing the configuration of the active site with one of two results.
Either the enzyme-substrate complex does not form at its normal rate, or, once formed, it does not yield products at the normal rate.
On the other hand, a non-competitive (allosteric) inhibitor binds to the enzyme at an allosteric site, a location other than the active site, and still manages to block substrate binding to the active site by inducing a conformational change that reduces the affinity of the enzyme for its substrate.
Because only one inhibitor molecule is needed per enzyme for effective inhibition, the concentration of inhibitors needed for noncompetitive inhibition is typically much lower than the substrate concentration.
The Michaelis-Menten equation is a tool for understanding enzyme kinetics, but it has limitations. It enables the calculation of an approximate value of the maximum velocity but not the accurate value.
It applies only to enzymes with only active sites and not allosteric sites, and it is used to know the velocity of non-regulatory enzymes but not regulatory enzymes.
To overcome these limitations, a Lineweaver-Burk plot is drawn to establish a relation between the reciprocals of substrate concentration and velocity.
The complete question is: MM equation for noncompetitive inhibitor. Elaborate!