And that basically amplifies it makes better the interaction between the orange chain, the catalytic chain and the red chain that regulatory chain. So each R regulatory subunit contains a zinc domain that contains the zinc metal atom that interacts with the C subunit, the catalytic subunit. So again, each one of these red regulatory chains in the dimer interacts with one of these catalytic chains in that catalytic trimer via this metal atom that is present within the end portion, the interface section of each one of these regulatory chains. Now, when scientists were basically studying this molecule, how exactly did they actually discover where the active side is found within this molecule? Well, instead of actually using the substrate molecules for this enzyme, they used an inhibitor, an irreversible inhibitor to this enzyme. They synthesized an irreversible inhibitor that resembles the two substrate molecules of this particular enzyme.