Allosteric enzymes have two distinct binding sites. What is the purpose of each type of binding site?

The active and allosteric sites are used interchangeably depending upon environmental conditions.

The active site only serves as a placeholder while all functional changes occur at the allosteric site.

The active site facilitates substrate binding, while the allosteric site binds regulatory molecules for activity control.

All binding occurs at the active site while the allosteric site is merely structural in significance.