Question

Which of the following type(s) of inhibitors cannot bind to a free enzyme?

• A. Uncompetitive
• B. Non competitive
• C. Competitive
• D. All of these

Answer 1

The correct option is A Uncompetitive

A competitive inhibitor resembles the substrate very closely structurally and competes with the substrate for binding to the active site of the enzyme. It binds to the active site and forms the enzyme-inhibitor complex which doesn’t give products. The inhibition is reversible. It can be reversed by increasing the substrate concentration. Increasing the substrate concentration increases the probability of substrate to bind with the enzymes and form products.
A non competitive inhibitor binds at a site other than the active site. It can bind to the free enzyme or the ES complex. It changes the shape of the active site such that substrate is not able to bind to it.
An uncompetitive inhibitor binds to any other site other than the active site. It cannot bind to the free enzyme.