And what these hormones ultimately do is they allow our body, they allow the cells of our body to actually activate these beta subunits and they activate the beta subunits by attaching phosphoryl groups. So when we release the hormones that ultimately basically these four beta subunits to form the following structure. Now, although this structure does contain partial activity, it is not yet fully functional. And to transform this molecule into a fully functional enzyme that can basically catalyze this particular reaction, what must happen is calcium ions must bind to these red structures. These red structures are the delta structures and the delta structures are actually calmodulent proteins. Remember that calmodulen is a protein that consents calcium ions.