Gram-Positive vs. Gram-Negative Cell Walls

in this video, we're going to do a side by side comparison of gram positive versus gram negative cells. And so in this video we're only going to be reviewing information that we already covered in our previous lesson videos. And so since there's no new information that's being covered, if you're already feeling really good about the differences between gram positive and gram negative cells, then feel free to skip this video if you'd like. However, if you're struggling or need even just a little bit more help then feel free to stick around because this video might be very helpful for you. And so notice that down below we have an image that is organized into a table and on the left hand side over here we are focusing in on gram positive cells. Whereas on the right hand side over here we're focusing in on gram negative cells. And so keep that in mind. So, one thing to note is that in both gram positive and gram negative cells there is a plasma membrane. All cells have a plasma membrane and so that is something that is similar between the two. They both also have a peri plasm or perry plasvic space which is the space or the gel like fluid in between the potato blight can and the cell membrane or the plasma memory. And so they both have a plasma membrane and a perry plaza. Now in terms of the peptidoglycan layer, noticed that the gram positive cells on the left, they have a thick layer of potato blight can. That is very, very thick here. In comparison to the layer of peptidoglycan over here with gram negative cells which is very thin. Um The gram negative cells are going to have lipoproteins that are going to help anchor the entire outer membrane to the potato black hand layer and the outer membrane is going to have lipo policy Sacco rides and or uh endo toxin or LPS and embedded within this outer membrane are also going to be pouring that will allow molecules to be transported across the membrane. Now the grand positive cells, they have these tech OIC acids, there are light biotech OIC acids which will connect directly to the cell membrane or the plasma membrane. And then there are wall to coke acids which do not connect directly to the plasma membrane and instead they're mainly embedded in the potato blight can layer. And so down below what we have is this little chart that helps to summarize a lot of those uh important key features. So in terms of the outer membrane, gram positive cells do not have an outer membrane, that outer membrane is specific to gram negative cells. And so the outer membrane is going to be present here and gram negative cells. And once again the outer membrane is this membrane that you see up above right here. Now. In terms of the peptidoglycan layer, both gram positive and gram negative cells have cell walls made of peptidoglycan. However, with gram positive cells they have a thick layer of peptidoglycan, whereas in gram negative cells they have a thin layer of potato black hand. And again that is being represented up above as well, where you can see the thick layer of potato blake can and gram positive and the thin layer of peptidoglycan and the gram negative. Now in terms of tech OIC acids, gram positive cells are going to have to colic acid so they will be present in grand positive cells however, and gram negative cells the tech OIC acids are absent, so gram negative cells do not have to coke acids and the liberal policy sacha rides are going to be absent in Grand positive cells, but they will be present and gram negative cells. And so really this little chart right here summarizes many of the most important and most tested on uh differences between gram positive and gram negative cells. And so it summarizes those key differences. And it's a good little chart to be able to study from. And so this here concludes our brief review of the main differences between gram positive and gram negative cells and we'll be able to get some more practice as we move forward. So I'll see you all in our next video.

in this video, we're going to talk about a pneumonic or memory tool to help you remember the key differences between gram positive and gram negative cells. And so really this pneumonic is down here in this image and the pneumonic is just long power point or PPT since PPT is an abbreviation for power point. And so all you need to do is think about those long power points that your professors used during lecture. And so when you think about long power point, this can help you remember that. Light bhopal is sacha rides or LPS or end a toxin as well as an outer membrane are associated with gram negative cells and they are not associated with Grand positive cells. And then the power point over here can help remind you that gram positive cells have a thick peptidoglycan layer, although they both had peptidoglycan. Gram positive cells have a thicker peptidoglycan layer. And so that's why we have the peptidoglycan associated here. And Grand positive cells also have to coexist acids that are specific to grant positive cells and they are not found in gram negative cells. And so all you gotta do is think about those long boring power points that your professors use and that can help you remember this little memory tool here and so hopefully that will be helpful to you guys in some way. And I'll see you guys in our next video.