Like monosaccharides, disaccharides are sugars but are formed by two monosaccharides joining together.
The most common disaccharides are maltose (glucose + glucose), sucrose (glucose + fructose) and lactose (glucose + galactose).
Sucrose is the transport sugar in plants, and the sugar commonly bought in stores. Lactose is the sugar bought in shops.
The joining of two monosaccharides takes place by a process known as condensation (yields H2O). During the reaction two hydroxyl groups line up alongside each other. One combines with a Hydrogen atom from the other, to form water. This allows a oxygen ‘bridge’, which is called a glycosidic bond.
The reverse of condensation is the addition of water, or hydrolysis.
CONTINUE TO :