Glucose:This monosaccharide is also called dextrose or grape sugar. It is widely distributed in nature and found in fruits, vegetables and cell sap. It is the most abundant carbohydrate found in corn sugar and is present in corn syrup, honey and molasses. In the animal body it is an end product of digestion of starch, sucrose, maltose and lactose. Glucose is the carbohydrate found in the blood of all animals and man where it serves as source of instant fuel or energy for the body. Glucose is oxidized in the body to produce energy. The normal blood glucose level should be 80 – 100 mg/dl.
Fructose: This is also a monosaccharide and is also known as levulose or fruit sugar. It occurs in fruits and honey. Fructose consumed in the diet is rapidly converted into glucose in the body.
Galactose: Galactose does not occur in the free State in common foods. It occurs in combination with glucose in lactose (a disaccharide) present in milk. During digestion, when milk is made into curds, glucose is converted into lactic acid and galactose is left behind. Galactose can be converted into glucose in the body and vice versa.