in this video, we're going to introduce signal amplification. And so once the signaling molecule binds to its receptor, that signal can be amplified inside of the cell in order to maximize the effect of the signal and generate a maximum cell response. And so, if we take a look at our image down below, over here on the left hand side, notice that here we're showing you a cells plasma membrane and so down below we're showing you the cytoplasm or the inside of the cell and up above with the blue background. Here, we're showing you the outside of the cell with the extra cellular fluid. And so notice that embedded inside of the cell membrane here we have a receptor and the signal molecule here in red, we know will bind to the receptor calls a confirmation. I'll change now. This confirmation will change. In some scenarios. There may be no amplification at all. And if there's no amplification, then that just means that not very many molecules are going to be activated. And so here we're only showing you one molecule being activated. And if there's only one molecule that's activated, typically that's going to lead to a smaller cellular response. And so, with no amplification, there's a smaller cellular response. But in other scenarios, the signal can be amplified. And so notice going in this direction, we're showing you signal amplification, and with signal amplification, many molecules are going to be activated. And so many we have one signaling molecule that leads to the activation of many molecules. And if many molecules become active, it activated than the signal is being amplified. And ultimately, that's typically going to lead to a larger cellular response. So again, signal amplification allowed for a larger cellular response so that that response can be maximized. Now it turns out that there are two types of enzymes that air commonly used to amplify the signal inside of the cell. And these two types of enzymes air called protein, kindnesses and protein phosphate tastes is now protein. Kindnesses are going to add a phosphate group to a substrate and protein. Phosphate taste is, on the other hand, are going to remove a phosphate group from the substrate, so protein, kindnesses and protein foster tastes are essentially doing the opposite of each other. Protein kindnesses add a phosphate group, whereas protein foster taste is removed. The phosphate group. Now why is it so important to focus on this phosphor relation? Uh, the adding of a phosphate group? Well, it's because phosphor relation again, the adding of a phosphate group to a substrate is going to alter or change a proteins activity, and how that proteins activity will be change is going to depend on the specific protein the specific scenario. But foster relation will typically lead to the alteration of a proteins activity, either by turning the protein on or activating the protein or turning the protein off or deactivating the protein and so down below notice. Over here on the right hand side of our image, noticed that we're showing you a D. Foss for elated protein over here on the left hand side. And so this D foster related protein does not have a phosphate group attached. However, the kindness enzyme is capable of again. Protein kindness is capable of adding a phosphate group to the substrate, and so the kindness enzyme is capable of taking the defaults for related protein and adding a phosphate group to it, so you can see the P here represents the phosphate groups, so here we have a phosphor related protein. Now the phosphate group. Typically the source is going to be a teepee, getting hydrolyzed into a D. P. So the phosphate group originates from the A T P. But ultimately, kindnesses are going to add phosphate groups to get phosphor related proteins. And again, phosphor related proteins are going to have altered activity. And so you can see the yellow border around the phosphor related protein to represent that altered activity. And so this could represent the activation of this protein. And so if it's being activated, then it could be part of signal amplification. So you could imagine that all of these proteins down below, over here in signal amplification are proteins that are getting phosphors related so that they become activated and generate a larger cellular response. Now, when the cell wants to remove that cellular response, essentially dampen the cellular response or turn off the cellular response, then it needs a way to get rid of the altered activity. So this is when phosphate cases can be, uh, important, because phosphate aces are going to remove the phosphate group. So again, protein foster taste is remove. The phosphate group substrate, so you can see the foster taste down below. Here is going to take the foster related protein and remove the phosphate groups so you could see the phosphate group is being removed. And that ends up regenerating the defrost for related protein that we have here. And so again, thes enzymes, protein, kindnesses and protein phosphate cases can be really important in signal amplification on DSO. This here concludes our introduction to signal amplification and we'll be able to get some practice applying these concepts as we move forward in our course, So I'll see you all in our next video.