In this video, we're going to briefly introduce 2 other classes of lipids, the steroids and the waxes. Steroids are a complex class of lipid that look significantly different than the other lipids we've discussed. This difference results from the fact that steroids are not composed of fatty acids. Instead, steroids are lipids made up of 4 fused carbon ring structures. A classic example of a steroid is cholesterol, which you may have heard of before because it is a common steroid important for the structure of animal cell membranes.
If we look at our image down below on the left-hand side, notice this molecule we are showing you is cholesterol, and it is a steroid because it has these 4 fused carbon ring structures, numbered 1, 2, 3, and 4. Cholesterol is a common steroid important for the structure in animal cell membranes. Meanwhile, on the right, we're showing you a zoom-in of an animal cell membrane, where cholesterol molecules are embedded within the phospholipids that are the major components of cell membranes as we learned from our last lesson video.
We will discuss the actual function of cholesterol in cell membranes later in our course when focusing specifically on the cell membrane. This concludes our introduction to steroids. Now, the other class of lipid that we're going to briefly talk about are waxes. Waxes are another class of lipid used for protection and for the prevention of water loss. Looking at the image on the right-hand side, we're showing you a structure that is a classic example of a wax because this structure is beeswax, as indicated by the bee featured here.
Notice that beeswax is made up of a fatty acid but also contains a long-chain alcohol group. Waxes can be used for protection purposes and prevention of water loss. It's essential to know that waxes are a class of lipid. Both steroids and waxes are types of lipids, and this is the main takeaway of this video. This concludes our introduction to steroids and waxes, and we'll be able to get some practice in our next couple of videos.
So I'll see you all there.