 All right, in the remaining videos for this week, we are going to talk about something called carbohydrates. You've probably heard of carbohydrates or carbs before, but we obviously have to talk about chemistry of carbohydrates. Just to break the word apart, carbon means carbon. Hydrate means water. So carbohydrates are basically molecules with carbon and a bunch of water stuck on them, sort of. When we think of carbohydrates, we usually think of food like sugars and starches. These are examples of carbohydrate molecules. There are different kinds of carbohydrates. You can break them into many categories. I'm going to break them into three categories. The simplest carbohydrates are called monosaccharides, and this is going to be my cartoon for a generic monosaccharide. Mono means one. Saccharide means sugar. Monosaccharides are usually referred to monosaccharides as sugars, and they have a tendency to taste sweet. The next simplest type of carbohydrate I'm going to call a disaccharide. Di means two. Saccharide again means sugar. This is going to be my cartoon for a generic disaccharide, and you'll see why in a little bit. Disaccharides are also generally thought of as sugars, and they generally taste sweet to us. You can see that disaccharides are basically made by connecting two monosaccharides to each other. The third type of carbohydrate is called a polysaccharide. Poly means many. You remember we talked about polymers in a previous video? Well, many sugars connected to each other. This is going to be my cartoon for a generic polysaccharide. The way that you make polysaccharides is you take a bunch of monosaccharide molecules and connect them to each other, more or less the same way over and over again. Polysaccharides, as a rule, do not taste sweet to us. They are some examples of polysaccharides are things like starch, cotton, things like that. So what I'm going to do in the upcoming videos is I'm going to go through each of these one by one and talk about them in detail. First one I'm going to talk about is monosaccharides. They are the simplest carbohydrates. They are used to build disaccharides and polysaccharides. We can get energy from them. If we're not using them to build bigger carbohydrates, we can take monosaccharides and break them into smaller pieces, and when we break them into smaller pieces, we get energy from them. So you can think of monosaccharides as sugars. We can break sugar molecules apart into smaller and smaller pieces, and that's how we get energy from sugar. There are many different kinds of monosaccharide molecules. These are some examples here. These are not the only examples. This one here, you don't need to know what it looks like. You don't need to know its name. But if you look, it has three carbons, one, two, three. Because of that, this molecules, carbohydrate molecules that have three carbon atoms have a special kind of name. They're called trioses. Tri means three. Oase is usually the most common ending for the name of carbohydrates. So triose means a monosaccharide with three carbon atoms in them. This is not the only triose molecule there is, but it's just an example of one. This is a different monosaccharide. It has four carbon atoms. One, two, three, four. Because of that, this kind of molecule is called a tetrose. Tetra, I believe, comes from the some Greek word that means four. But if you see tetrose, that means you're talking about a monosaccharide that has four carbon atoms in the molecule. This one, you guessed it, has five carbon atoms. It is an example of a pentose monosaccharide. Pentose, penta means five. So if you remember pentane, that's not a carbohydrate, but it does have five carbon atoms in it. Pentose means it's a monosaccharide with five carbon atoms in it. And this one has six carbon atoms, so it's called a hexose monosaccharide. And you can have carbohydrates with seven carbons, and that would be called heptose. Eight carbons would be called octose, etc., etc. And you can imagine on a quiz or a test, I can show you a monosaccharide molecule, maybe like this one, and I could ask you what kind it is. It is a triose, tetrose, pentose, hexose, whatever. And all I expect you to do is look at this thing and figure out how many carbons it has. It says, oh, it's got four carbons. It must be a tetrose, something along those lines. So what do I want you to know? I want you to know what triose, tetrose, pentose, etc., are. You should be able to recognize them. This, you should know, glucose is probably the most important carbohydrate that we deal with, that humans deal with in the world. So you should know that glucose is a hexose monosaccharide. So you should memorize that or write it down. You should know what monosaccharides are used for. We can either break them into smaller pieces and get energy from them, or we can connect them to each other and make bigger carbohydrates, or we can connect them to each other and get bigger carbohydrates. And that's the end of this video. See you in the next one.