And once the active sites are free these catalytic subunits and we have two of them can basically go on and catalyze all these different types of target enzymes via the process of phosphorylation. So once again, cyclic adenosine monophosate binds to allosteric sites found on the regulatory chains. This stimulates the dissociation of the regulatory subunes from the catalytic subunits. And once the catalytic subunits basically dissociate those active sites become free. And now the substrate molecules can go on and buy onto those active sites. And by the way, this is the active site here and this is the active site here for this second green subunit.