What are Carbohydrates? | Biology Review


When carbohydrates burn they yield carbon and water, so that’s why the name carbohydrate comes from carbon and water. Now, carbohydrates include sugars and starches. Sugars and starches are the main source of energy that your body uses, so you can see that carbohydrates are very important.

Now, there’s 3 basic types of carbohydrates I want to go over. First being monosaccharide. It’s a really long word, has a complicated spelling with 2 c’s in a row, but more important than the spelling is what a monosaccharide is. it’s a simple sugar such as glucose, fructose, and ribose.

Now we call these sugars monomers because these sugars are monomers for more complex ones. Notice here in monosaccharides, we have the prefix mono- which means 1. Then I just mentioned that these are monomers which has that prefix again of mono- meaning 1.

Now you may be familiar with polymers, which has the prefix of poly- which means more than 1. Basically, these sugars are monomers for more complex molecules, so these are single molecules that are the building blocks to be able to join together with other molecules to form polymers.

Remember that because we’re going to talk about that more in a little bit. The second type of carbohydrate is a disaccharide which is a double sugar such as sucrose, maltose, and lactose. Now, sucrose is what we would call table sugar—it’s the type of sugar used for everyday use, for baking, coffee, that sort of thing.

Now the third type of carbohydrate is starches, which are large biological polymers that consist of straight or branched chains of monosaccharides linked together. Let’s go ahead and break that down because that’s kind of complicated. These are large biological polymers, so we see that prefix of more than 1.

Remember, I talked about these being monomers—they’re going to join together to form the polymers. We see that played out right here because these monomers joined together to form polymers, and we even see that confirmed, or spoken of, again later in this definition.

These polymers consist of straight or branched chains of monosaccharides linked together, so starches are basically made up of monosaccharides linked together either in straight or branched chains.

Now in complex sugars, the monosaccharide monomers combine by condensation reactions, where water is removed in the form of a hydrogen atom from 1 monosaccharide and a hydroxyl group from an adjacent monosaccharide. That’s a look at the 3 types of carbohydrates.



by Mometrix Test Preparation | Last Updated: May 17, 2019