In this video, we talk about our phosphoglycerides. Now we're going to say here that our phosphoglycerides, also called our Glycerophospholipids, are phospholipids with a Glycerol backbone and 2 fatty acids. Now, here we're going to say again they're composed of a head and a tail region. The head is a phosphate group extended with an Amino Alcohol head group, and the tails, there are 2 fatty acids attached through Ester Bonds. Now, here we're going to say they are classified based on the Head Group Attached to the Phosphate Group. If we take a look here at our types of Phosphoglycerides, we have our two classes, which are our Sphingolipids and our Lecithin. Here, the differences come with the different types of head groups involved.

With Cephalin, the head group is an Ethanolamine. And here Nitrogen is making 4 bonds, so it is positively charged, Its groups would be Hydrogens. An example of this would be this structure. We can see the head group here, our Ethanolamine. We have our phosphate group. We have our glycerol backbone in blue. And then, notice that we have 2 fatty acids. They could be saturated or unsaturated. They could be the same. They could be different. Now, here with Lecithin, its head group is different. Here, its head group is Choline. Notice that here, instead of having hydrogens attached to nitrogens, we have methyl groups and there are 3 of them. Here we have our head group, our phosphate group, we have our glycerol backbone, and our 2 fatty acids. Again, they could be saturated or unsaturated; that's not important here. The defining characteristics of these two classes are in the types of head groups attached.

Now, here finally we can say that phosphoglycerides again are the most abundant lipids in all cell membranes. Remember, they help to make the lipid bilayer. That's why they're found in so many I mean, all cell membranes, right. So just keep this in mind when we're talking about our phosphoglycerides; we have 2 classes. Those classes depend on the type of head group attached.