About the following Michaelis-Menten curve, true statement is:
A. Modifier can affect the catalytic site by binding to the allosteric site
B. Allosteric modifiers changes the binding constant of the enzyme but not the velocity of reaction
C. Allosteric modifier hinds in a concentration dependent manner
D. Adding more substrate to the enzyme can displace the allosteric modifier
Ans: A. Modifier can affect the catalytic site by binding to the allosteric site
Ref: Harper 30/e p82, 91)
- In allosteric modification, the modifier binds to the allosteric site and changes the rate of enzymatic action at the catalytic site.
- Since it is not a type of competitive inhibition, the modifier does not bind in a concentration dependent manner and adding substrate doesn’t overcome the inhibitory effect.
- Allosteric inhibition usually decreases the velocity of the reaction without any change in Km.