And once they bind, an endocytosis process takes place in which the cell membrane basically invaginates and it engulfs this structure. And what happens is once that engulfing process takes place, this catalytic A chain is released into the cytoplasm. So once bound, the catalytic A chain moves into the epithelial cell of the small intestine v the process of endocytosis. Now, what happens once it makes its way into our cell? So let's suppose that our G protein coupled signal transduction pathway is actually turned on. And so what that means is this g protein is in its GTP phase and so it is bound onto the adenylate cyclase and it continually stimulates the cyclase to basically produce the camp, the cyclic adenosine monophosphate phosphates which stimulate the PKA.