Carbohydrate – Monosaccharides, Disaccharides & Oligosaccharides

Monosaccharides are as small as carbohydrates get. Said another way, monosaccharides cannot be split into smaller carbohydrates. All other carbohydrates are made up of monosaccharides linked together. For instance, disaccharides are composed of two monosaccharides linked together.The three disaccharides found in our diet, including their monosaccharide building blocks, are listed in Disaccharides Building Block Table below.

Glucose and fructose can be found in foods either independently or as part of larger carbohydrates. Fructose is what makes honey and many fruits sweet and is used commercially as a sweetener either as fructose or high fructose corn syrup. On the other hand, while some galactose is found in certain foods, it is mostly found as part of larger carbohydrates. 

Looking at Disaccharide Building Blocks Table above we see that glucose is one-half of the disaccharides lactose and sucrose and both halves of maltose. Maltose, or malt sugar, may be part of our diet naturally in seeds or alcoholic beverages. Sucrose is derived from the sugar cane plant and the beet, which and the sucrose rich product is called “sugar”.

Lactose is the primary carbohydrate found in milk and dairy products. Nutrition scientists often refer to monosaccharides and disaccharides as “simple sugars” because of their relatively small carbohydrate size and their sweet taste. Carbs and Sweeteners Table presents the relative sweetness of simple sugars and compares them to sugar alcohols and artificial sweetners.