Carbohydrates

1. Organic Compounds

An organic compound is a compound that contains carbon and at least one hydrogen atom.

There are four types of organic compounds:

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids

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Organic Compounds

Compounds that contain the element carbon.

2. Structure & Function of Carbohydrates

Carbohydrates are molecules that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio. Carbohydrates are used in our body and broken down into sugars that our bodies and our cells use for energy.

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Carbohydrates

Organic compounds that can be broken down into simple sugars by the body and used as a source of energy.

3. Role of Carbohydrates in Your Body

There are three main categories of carbohydrates.

3a. Monosaccharides

A monosaccharide is the most simple type of carbohydrate that you can have; it's made of just one sugar unit.

hint

The prefix mono means one. That will help you remember that monosaccharides are simple and they're made up of just one sugar unit.

Monosaccharides are the building blocks for larger molecules. Larger carbohydrates are built from these monosaccharides.

IN CONTEXT

A common example of a monosaccharide is glucose. Your body and your cells use glucose for energy. Glucose is necessary for the process of cellular respiration to occur.

Here is a diagram of what glucose looks like.



Glucose is a six-carbon sugar, so it has a carbon backbone. When you’re talking about carbohydrates and their structure, they have a carbon backbone with hydroxyl groups coming off of the carbon.

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Monosaccharides

Simple carbohydrates composed of single sugar units.

3b. Oligosaccharides

Oligosaccharides are a little bit more complex than monosaccharides. They are when two or more monomers are joined by dehydration synthesis. When there are exactly two joined together, you call that a disaccharide.

IN CONTEXT

In the diagram below you should notice the molecule glucose. The molecule next to it is fructose.



Both individually are monosaccharides, but when they're joined together by dehydration synthesis, they form a disaccharide. This disaccharide here is called sucrose, what we typically call "table sugar".

Dehydration synthesis is how these monosaccharides are bonded together. Generally, you would have two hydroxyl groups (OH + OH) together. If you take out one, two of the hydrogens and one oxygen, it forms water (HOH). What you have left is the O in between them, like you see on the diagram here. Then water is formed as a byproduct. That's what happens in dehydration synthesis when two monosaccharides are joined together.

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Oligosaccharides

Carbohydrates composed of two or more sugar units combined; include a type of carbohydrate called disaccharides, which are composed of exactly two sugar units.

3c. Polysaccharides

The third type of carbohydrate is polysaccharides. The prefix poly means many. So you have many sugar units joined together to form complex carbohydrates, such as starches and cellulose.

You can have up to thousands of monomers connected by dehydration synthesis. The reason that these are complex carbohydrates is that they have a lot more energy.

Here is a diagram of what a polysaccharide looks like.

IN CONTEXT

Think of the complex carbohydrates like starches that you eat. You get a little bit more energy from them because of the many bonds that form between them. Those bonds store energy, which can be used to produce more energy later on. So starch is a common example of a polysaccharide.

Cellulose is another example of a polysaccharide. Cellulose is a plant-derived polysaccharide and is how glucose is stored in plants and gives the plant structure. Generally, you cannot digest cellulose. Your digestive system doesn't have the enzymes to break cellulose down, but you benefit from cellulose by eating plants because it adds fiber to your diet.

term to know

Polysaccharides

Carbohydrates composed of many sugar units joined together.