In this video, we're going to introduce yet another type of lipid called the phospholipid. Phospholipids, as their name implies, are lipids themselves. In fact, they are a large class of lipids. Also, as their name implies with the "phospho" here, these are a large class of lipids that contain a phosphate group, which you all should be familiar with as one of the functional groups. Phospholipids are actually a major component of all cell membranes, and we'll be able to see this in our image below.
Now, later in our course, we'll talk more about cell membranes, but in this video, we're focusing specifically on phospholipids. Phospholipids are what we call amphipathic molecules, and "amphipathic," recall, is just a fancy word that means it contains both hydrophilic or water-loving and hydrophobic or water-fearing groups. Phospholipids are amphipathic molecules with a hydrophilic head and hydrophobic tails. If we take a look at our image below at these phospholipids, notice that on the far left, we're showing you a cell, and we're zooming in specifically to the cell's membrane, which is this little area right here.
When we zoom into the cell's membrane, what we'll see is that the vast majority of the membrane is made up of these little structures, these units that we call phospholipids. If we zoom into just one of these units and blow it up, it would look like what we see right here. Notice that it really has two regions: it has this head region that's up here, and then it has the two tails that extend down below. The head region is a hydrophilic head, which means that it is water-loving and interacts with water. The two tails that we see down below are hydrophobic tails, meaning that they are water-fearing. These tails are trying to get away from water. Because we have a single molecule here with both hydrophilic groups and hydrophobic groups, that is why we call this an amphipathic molecule.
If we were to zoom into the structure of the phospholipid even more, we could see the details of its chemical structure, which include fatty acids (these yellow regions here), a glycerol molecule, and a phosphate molecule at the top. This phosphate functional group is why we call them phospholipids. This concludes our introduction to phospholipids, and we'll be able to talk more about them later in our course when we're discussing cell membranes. But for now, this concludes our introduction to phospholipids, and we'll be able to get some practice as we move forward in our course.
So, I'll see you all in our next video.