During the process of signal transaction. There many steps to this process. The initial component of signal transaction begins with reception or recognition at the site of the cellular membrane. So you have your cellular membrane and then embedded in the cellular membrane will be your receptor, which will detect or receive or recognize the environmental stimuli. In this particular problem, epinephrine will act as your like in molecule, which will be in which is from the extra cellular environment. The G protein couple receptor will act as your receptor, which will recognize and lead the recognition step of the signal transaction pathway after epinephrine binds to the G protein coupled receptor as shown here. So this epinephrine is going to bind to the G protein coupled receptor Um, that is located in the cellular remembering Okay, this G protein coupled receptor will undergo a confirmation. I'll change, which will lead to the activation of the G protein, which was which is on the side of Solich side of the cellular membrane. This jeep protein couple, I mean, sorry. This G protein will then transducer this signal to activate another enzyme that's located in cellular membrane, known as a dinner lean cyclists. This identically inside place will undergo chemical reactions and confirmation all changes which will then reap, which will then produce Sigh, click A and P or Camp Sigh click. A MP will then act as the second messenger in this system, which will then activate other affect er's downstream of this signal transaction pathway. So the second messenger in this pathway is sigh, Click A and P.