Sugar explained..

Sugar explained under these names: Glucose, galactose and fructose.

A pinch of purified glucose on the tongue gives only a mild sweet flavour, and galactose hardly tastes sweet at all, but fructose is as intensely sweet as honey and, in fact, is the sugar primarily responsible for honey's sweetness.

Sugars are derived primarily from plants, except for lactose, which come from milk and milk products.


Glucose
Commonly known as blood sugar (dextrose), glucose serves as an essential energy source for all the body's activities.  Its significance to nutrition is tremendous.

Fructose
Fructose is the sweetest of the sugars.  Fructose occurs naturally in fruits and honey; other sources include products such as soft drinks, ready-to-cereals, and desserts that have been sweetened with high-fructose corn syrup.  It is sometimes known as fruit sugar or levulose.

Galactose
Its part of lactose.

Maltose is (glucose plus glucose).  Sometimes known as malt sugar.  Maltose is produced whenever starch breaks down - as happens in plants when seeds germinate and in human beings during carbohydrate digestion.  It also occurs during the fermentation process that yields alcohol.  Maltose is only a minor constituent of a few foods, most notably barley.

Sucrose is (glucose plus fructose).  Commonly known as table sugar, beet sugar, or cane sugar.  Also occurs in many fruits and some vegetables and grains.  Because the fructose is in a position accessible to the taste receptors, sucrose tastes sweet, accounting for some of the natural sweetness of fruits, vegetables, and grains.  To make table sugar, sucrose is refined from the juices of sugarcane and sugar beets, then granulated.  Depending on the extent to which it is refined, the products becomes the familiar brown, white, and powdered sugar available at grocery stores.

Lactose is (glucose plus galactose).  Commonly known as milk sugar.  The principal carbohydrate of milk.  Lactose contributes about 5 percent of milk's weight.  Depending on the milk's fat content, lactose contributes 30 to 50 percent of milk's energy.