Y. It’s Halloween! A woman eats a few bars of dark chocolate. Dark chocolate contains a lot of theobromine, which is a potent methylxanthine. After consuming all this chocolate, the woman is given a fright by her friends, causing the secretion of epinephrine. Epinephrine binds to several G-protein coupled receptors, including the β1 adrenergic receptor. The β1 adrenergic receptor activates adenylate cyclase. Juxtaglomerular cells (these are in the kidney) express adrenergic β1 receptors. These juxtaglomerular cells synthesize an enzyme called renin. Explain (from the binding of the ligand to the cellular output) what happens in these juxtaglomerular cells after eating this much chocolate and receiving this big fright.