Question

An allosteric substance influences the enzyme activity by

• A. Competing for catalytic site.
• B. Changing the specificity of enzyme for substrate.
• C. Changing the conformation of the enzyme by binding to site other than catalytic site.
• D. All of the above.

Answer 1

The correct option is C Changing the conformation of the enzyme by binding to site other than catalytic site.

Competitive inhibitors are the enzymes which compete with the substrates for the active sites of enzyme. Allosteric modulators are the one which bind to a separate allosteric site on the enzyme and do not compete for the active site. Usually binding of an allosteric modulator brings about conformational changes in the enzyme which can increase the reaction rate (positive allosteric modulation) or decrease the reaction rate (negative allosteric modulation).