So now that we know from our last lesson video that cell signaling requires a minimum of two key components the like and or the signaling molecule and the receptor in this video, we're going to focus on the three steps of cell signaling. And so cells received external signals in a Siris of three steps that we have number down below number one, number two and number three. And so the very first step of cell signaling is going to be reception or, in other words, like and binding. And so in this first step of reception, the ligand or the signaling molecule is going to bind to a very specific receptor, causing the receptor to change its confirmation or to change its shape. And so if we take a look at our image down below, which will notices, um, here, this membrane represents the cells plasma membrane that's separating the outside of the cell from the inside of the cell. And so over here on the left hand side, what we have is the outside of the cell or the extra cellular fluid, and over here on the right hand side and the yellow background, what we have is the inside of the cell or the cytoplasm, and so notice that embedded here within the membrane is a receptor and the signaling molecule or the like, and is here in red. And so in the very first step of cell signaling, which is again reception, what happens is the lie. Gand, or the signaling molecule here is going to bind to its receptor. Like what we see here, the ligand is now bound to the receptor, and when the ligand binds to the receptor, it's going to cause a confirmation will change in the receptor, which will lead to step number two over here. And so in step to what we have is trans duck shin. So after the lie again binds to the receptor and causes a confirmation, all change in the receptor. This is going to lead to a pathway of interactions in the cell that ultimately is going to trans deuce as implied by transaction or, in other words, convert transducer or convert the signal to change to a change within the cell. And so, in the process of transaction, there's really just gonna be a Siris of interactions, and this Siris of interactions is ultimately going to convert that external signal or that external lie game, uh, into a change within the cell. So let's take a look at it. Step number two down below right here. And so notice. Step Number two is trans deduction. And so, with transaction, there's a Siris of events. Notice that we have a B and C here within step number two, and so in transaction. What happens is the confirmation I'll change within the receptor from step number one is going to lead to a Siris of events where some molecule is going to become activated, which could lead to the activation of another molecule, which could lead to the activation of another molecule and so on. And ultimately, the trans duck sh in step here is going to vary significantly between different pathways. But ultimately, with transaction, there's gonna be a Siris of events, and at the end of transaction it leads to the last step, which is the cellular response. And so that is our step number three of cell signaling. And so the cellular response is going to be the end result of the cell signaling pathway that is going to end up causing a physical or chemical change in response to the extra cellular lie again that originated. And so the signaling molecule or the lie again and ultimately is going to be triggering this cellular response. And so the cell responses generated, uh, in response to the extra cellular signaling molecule or the like. And and so really, this here concludes our introduction to the three steps of cell signaling. And again, as we move forward in our course, we'll be able to talk more and more about cell signaling, so I'll see you all in our next video.