Chapter 7, Problem 1RE

RECALL What features distinguish enzymes that undergo allosteric control from those that obey the Michaelis–Menten equation?

Interpretation Introduction

Interpretation:

The difference between the enzymes that undergo allosteric control and the ones that obey the Michaelis–Menten equation is to be discussed.

Concept introduction:

The allosteric enzymes have multiple sites called allosteric sites. These enzymes change their shape when they bind to the substrate.

The binding of a molecule other than that of the substrate molecule can cause hindrance in the activity of the enzyme.

Answer to Problem 1RE

Solution:

The allosteric enzymes have multiple subunits and allosteric sites, whereas the Michaelis–Menten enzymes have a single active site, so there is a difference between the activities of these two enzymes. The rate of the concentration and substrate concentration graph for the allosteric enzyme is sigmoidal, while for the Michaelis–Menten enzyme, it is hyperbolic.

Explanation of Solution

The differences between the enzyme that undergo allosteric control and the ones that follow Michaelis–Menten equation are given in the table below:

Allosteric enzyme	Michaelis-Menten enzyme
The allosteric enzymes have a number of allosteric sites or active sites.	These enzymes have a single active site to which a particular substrate can bind.
The multiple sites show the property of cooperativity, which means the binding of one molecule facilitates the binding of another molecule.	The substrate binds to the active site of the enzyme and leads to the formation of products.
The allosteric enzymes exist in two states: R-state and T-state.	The enzymes exist in a single native form only.
These enzymes show sigmoidal curve in the graph of reaction rate versus substrate concentration.	The enzymes show hyperbolic curve in the rate of the reaction versus substrate concentration graph.

Conclusion

Hence, it can be concluded that the allosteric enzymes are unique as compared to the other enzymes because of their capability of adaptation to various conditions in the environment and are much different from the enzymes that follow Michaelis–Menten equation.