Question

cooperativity is a form of allosteric activation in which...

the product of a metabolic pathway serves as a competitive inhibitor of an early enzyme in the pathway.
all of the enzymes in a metabolic pathway are contained within a single multienzyme complex.
completion of one step in a metabolic pathway is required before a subsequent step can occur.
binding of a substrate molecule to one active site in a multisubunit enzyme stimulates the binding of substrate molecules to the active sites of other subunits.

Explanation:

Cooperativity in allosteric activation refers to the phenomenon where the binding of a substrate to one active site in a multisubunit enzyme affects (stimulates) the binding of substrate to other subunits.

• The first option describes feedback inhibition (not cooperativity).
• The second option is about multienzyme complexes (not cooperativity).
• The third option is about sequential steps in a pathway (not cooperativity).

Answer:

binding of a substrate molecule to one active site in a multisubunit enzyme stimulates the binding of substrate molecules to the active sites of other subunits.