Carbohydrates are complex organic compounds composed of carbon, oxygen and hydrogen. Carbohydrates provide a major source of calories for the body. Although all carbohydrates have the same chemical composition, they differ in the complexity of its molecular structure. So we have:
1. simple sugars or monosaccharides (glucose and fructose) - sweet taste, water-soluble but dissolved in water can not be separated.
Glucose is the most widespreaded monosaccharide in nature. Can be found in the blood of all mammals, and in honey and grapes. That's why other name for glucose "grape sugar" and "blood sugar."
Glucose has a very sweet taste, it is water-soluble and is also indispensable for the maintenance of life, because when broken down in the cytoplasm of living cell it releases large amounts of energy needed for many vital functions.
Fructose is very sweet sugar, water- soluble. It can be found in fruit – that's why it is called fruit sugar or fructose.
2. complex carbohydrates:
· disaccharides (oligosaccharides) - (sucrose and lactose)
· polysaccharides (starch and cellulose)