Allosteric site = a binding site on the protein other than the active site
Allosteric effector molecules don't resemble the structure of the substrate. So, they cannot bind to the active site. Instead, they bind to an allosteric site and alter the conformation of the protein such that the activity of the protein is affected.
Allosteric effectors can be activators or inhibitors, i.e. the conformational change in the structure can activate or repress the protein function.
Allosteric proteins can also be regulatory proteins (Activators or inhibitors) or enzymes.
