Now, let's move on to diagram B. So this is the second site, the second point in the pathway where the cell can actually deactivate, shut down that pathway, and this is when that epinephrine is bound onto the site on the beta adrenergic receptors. So what is the function of this structure? Well, basically the epinephrine receptor complex actually is used to stimulate the transformation of the GDP alphagin form into the GTP alphagin form. And the question is, how can the cells inactivate the epinephriceptor complex and prevent any further activation of the alpha G proteins? So there are two different ways.