Interpretation:
From the given experimental data both in absence and presence of its inhibitor a Lineweaver–Burk plot is to be drawn and values of
Concept introduction:
An inhibitor may be defined as a molecule that binds with the enzymes and decreases the activity of enzyme toward the substrate and this decrease in enzyme activity is called enzymatic inhibition.
Enzymatic inhibition can be of many types. When substrate and inhibitor of an enzyme compete with each other to bind with the enzyme and both of them are structurally same it is known as competitive inhibition. On the other hand, when inhibitors don’t compete with the substrate and both of them can bind to the enzyme at their specific site present on the substrate it is known as noncompetitive inhibition.
To determine the rate of the reaction, experimental data must be put into Lineweaver Burk plot where the x-axis represents the values of
Answer to Problem 60RE
Plot the reciprocal of substrate concentration along the x-axis and the reciprocal of velocities (both in the presence and absence of inhibitors) along the y-axis.
Before drawing the plot, the data needs to be modified so that it can be put into Lineweaver–Burk plot. The modification of the data is
The Lineweaver–Burk plot from above data is as follows:
From this plot,
Or,
The value
So, the value of
The
The value of
By comparing these two plots it can be said that it is a type of noncompetitive inhibition.
Explanation of Solution
In the case of competitive inhibition, the substrate and inhibitor compete with each other to bind with the active site of the enzyme. By increasing substrate concentration, the effect of competitive inhibition can be discarded. In high substrate concentration
In the case of non-competitive inhibition, inhibitors bind with the allosteric site of the enzyme and enzyme itself can bind with both substrate and inhibitors. It is possible because it has two different sites for both inhibitor and substrate. When the inhibitor binds with an enzyme it blocks its activity even if the substrate is also bound to the enzyme. These inhibitors do not change the substrate affinity of the enzyme so the
In this Lineweaver Burk plot,
The
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Chapter 6 Solutions
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