In this video, we're going to talk about carbohydrate functions. Carbohydrates are structurally and functionally diverse, meaning that they can do so many different things for the cell because they can take on so many different types of structures. However, there are just 2 main functions that you all should be aware of when it comes to carbohydrate functions.
The first function that you all should be aware of is structural support. Some carbohydrates are used specifically to build the structures of cells, either within cells or on the outside of cells. For example, cellulose and chitin are two classic examples of some polysaccharides that are used for structural support. There are some others as well, for example, peptidoglycan might be one that you may or may not have heard of, but we're going to focus specifically on cellulose and chitin.
The second primary function that you should know carbohydrates have is energy storage. Carbohydrates are specifically used for short-term energy storage and can provide energy to living cells. For example, starch and glycogen are both examples of carbohydrates that are used for short-term energy storage.
Let's take a look at our example down below to focus on the polysaccharides that are in plants and animals and the functions they have. Notice that we have this image of a grid where the first column has the function, whether it is structural support like this Bob the Builder guy, or energy storage like these batteries. Then we have the polysaccharides found specifically in plants here in this column, and the polysaccharides found specifically in animals over here in this column. We are showing you 2 structural support carbohydrates, one in plants and one in animals, and also 2 energy storage carbohydrates, once again one in plants and one in animals. It's a nice little grid.
When we're talking about structural support, a classic example of a polysaccharide in plants that's used for structural support is cellulose. Cellulose is actually the most abundant carbohydrate found in plant cell walls. When we take a look at plants like this leaf right here and we zoom in on its structure, you'll notice that the cell walls of these plants contain cellulose. It is used to build cell walls and that's why it is structural support.
A structural support carbohydrate in animals is going to be what we see over here, which is chitin. Chitin is a structural support carbohydrate found in the exoskeletons of insects and crustaceans such as lobsters. If we were to zoom into the exoskeleton shell here of this lobster, we would see that chitin would be found within its structure. Chitin's structure is complex, and we don't really need to worry about its particular structure so much. Just knowing that chitin is an example of a structural support carbohydrate that's used to build the structures of exoskeletons.
In terms of energy storage, we're showing you 2 as well over here in plants. Plants mainly store their energy in the form of starch. Starch is going to be the storage form of glucose specifically in plants, and you'll find lots and lots of starch inside of potatoes like this one over here. And then over here we have an animal liver, and in animals, they store their energy in the form of glycogen. Glycogen is a polysaccharide or carbohydrate whose main function is to store glucose in animal cells.
This here concludes our introduction to carbohydrate functions, and we'll be able to get some practice applying these concepts in our next few videos. So, I'll see you all there.
