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. And in this inactive form, both of these active sites are basically occupied by regions of the regulatory subunits. And the sequence of amino acids found on the regulatory subunit that binds onto the active side is known as the pseudosubstrate sequence. So in this R two C two complex it's the pseudosubstrate sequence of the R subunits that binds onto the active side and occupies that active side.