Question

Choose a False statement:

Allosterity can not be negative

none of the answers are correct

Homotropic regulation occurs when a normal ligand of the protein is the allosteric regulator

Heterotropic regulation occurs when a different ligand affects binding of the normal ligand

Positive cooperativity corresponds to positive homotropic regulation

Answer 1

Allosteric regulation / Allosterity is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site.Effectors that enhance the protein's activity are referred to as allosteric activators, whereas those that decrease the protein's activity are called allosteric inhibitors.

So now we know about Allosterity , So we know that allosterity can increase or decrease binding capacity of an enzyme . So Allosterity can have negative impact on binding capacity of enzyme. Hence it can be negative.

In case of Homotropic allosterity , regulation occurs when a same ligand of the protein (same substrate) is the allosteric regulator.Most of the time it is an activator of the enzyme.

In case of Heterotropic allosterity , regulation occurs when a different ligand affects the binding of the substrate.

Hence from the following option (a) is only wrong ,as allosterity can have both positive and negative impact.