In this video, we're going to begin our lesson on lipids. Lipids are actually a very interesting class of molecule because they are highly diverse in both their structure and their function. It makes it a little bit tougher to organize the lipids because they are so different in their structure and their function. However, one thing that all lipids have in common is that all lipids are hydrophobic biomolecules, and that means that they are going to be insoluble in water, meaning that they will not mix well with water because they are hydrophobic or water fearing. Although all lipids are hydrophobic, sometimes lipids can also be what's known as amphipathic. Amphipathic means that they have both hydrophobic groups that are water fearing and hydrophilic groups that are water loving within the same molecule. We'll be able to see examples of amphipathic molecules as we move forward in our course. But it's important to keep in mind that although they are all hydrophobic, sometimes they can be amphipathic, having hydrophobic and hydrophilic groups.
Lipids are also a really interesting category of molecule because they are unlike all of the other classes of biomolecules, which include carbohydrates, proteins, and nucleic acids. Carbohydrates, proteins, and nucleic acids all use consistent monomers to build polymers. However, the lipids do not have a consistent monomer and so do not form long chains of polymers like other biomolecules. They are unlike the other classes biomolecules and they don't form long chains like what we saw in our previous videos.
Once again, there are lots of different types and classes of lipids, and we are not going to talk about all of the different types and classes of lipids, but we are going to talk about some of them. Lipids include fats and oils, phospholipids, steroids, and waxes. Notice that we have a picture of some butter and some vegetable oil oil here, perhaps some olive oil. This represents the fats and oils, which are important for long-term energy storage in animals and plants. We'll get to talk a lot more about fats and oils as we move forward in our course. This is just a brief introduction to them.
The second type that we have here are the phospholipids, which are a major component of cell membranes. We'll get to talk a lot more about phospholipids and cell membranes as we move forward in our course, but they are a type of lipid. Over here in the corner, what we have is an interesting looking structure which represents a steroid. Steroids are going to be an important component of plasma membranes as well. We'll get to talk about cholesterol and how that's an example of a steroid. Moving forward in our course, we'll be able to talk more about that. Steroids can also function as hormones. For example, testosterone and estrogen, which you may have heard of before, are examples of steroids and examples of lipids, for that matter. We'll talk more about these as we move forward in our course.
The last type of lipid that we're going to be talking about moving forward in our course are the waxes. Waxes are going to serve in the protection and prevention of water loss. An example of a wax is beeswax, for instance. Once again, we'll get to talk more about them as we move forward in our course. But for now, this concludes our introduction to lipids and some of the different types of lipids, and I'll see you all in our next video.