Difference Between Sugars & Carbohydrates

Mar 11, 2011 | By Ruth Coleman

Sugars are a type of carbohydrate, and all carbohydrates are categorized by their number of simple sugar units. Glucose and fructose, simple sugars also called monosaccharides, have one simple sugar unit. Sucrose and lactose have two simple sugar units, and are also called disaccharides. Some medical disorders, such as diabetes, involve the metabolism of sugars and carbohydrates.

Relationship

The term carbohydrates includes starch, fiber, cellulose, glycogen and sugar. All carbohydrates are made of carbon, hydrogen and oxygen, and most of them have these molecules arranged in a specific ratio. Carbohydrates are classified based upon how many simple sugar units they have. There are monosaccharides, disaccharides, oligosaccharides and polysaccharides, but all carbohydrates form part of the structure of cells or provide a fast source of dietary energy.

Simple Sugars

Monosaccharides are also referred to as the simple sugars, and they are classified based upon how many carbons they have. The smallest monosaccharides are called trioses because they have three carbons. Those with four carbons are called tetroses; those with five carbons are referred to as pentoses; the simple sugars that have six carbons are the hexoses. Most of the simple sugars in the body's cells are pentoses and hexoses.

Other Carbohydrates

Glucose and fructose are examples of monosaccharides. The disaccharides are carbohydrates that have two monosaccharide units, or two simple sugar units. Sucrose, lactose and maltose are all disaccharides. The oligosaccharides have two to 10 monosaccharide units, and they form part of the membranes of cells and proteins of certain structures inside of the cells. Polysaccharides have many monosaccharide units and include starch and glycogen -- the storage form of carbohydrates.

Carbohydrate Intolerance

The medical term carbohydrate intolerance describes disorders that involve carbohydrates and sugars. Disaccharides like sucrose and lactose are broken down into monosaccharides in the small intestines. For this to happen, however, people must have a specific enzyme, which is a protein that speeds up the time a reaction will take. Without these enzymes, the disaccharides do not break down and this causes water to move into the small intestines, which results in diarrhea.