Disaccharides CH1

Disaccharides

Disaccharide composed of two monosaccharide units bonded together with the formation of a glycosidic bond and the elimination of water. This is an example of a condensation reaction.

The diagram shows water being removed from between C4 of one glucose molecule and C1 of the other. The bond form between glucose molecules is a glycosidic bond. It is between C1 and C4 so it is called the 1-4 glycosidic Bond because the disaccharide molecule is straight and not twisted the bond is an alpha 1-4  glycosidic Bond.

This table summarises the information about disaccharides

Disaccharide

Component Monosaccharide

Biological Role

Maltose

Glucose + Glucose

In geminating seeds

Sucrose

Glucose + Fructose

Transport in phloem of flowering plants

Lactose

Glucose + Galactose

In mammalian milk

Testing for the presence of sugars

The Benedict’s test detects reducing sugars in a solution. The test is carried out as follows equal volumes of…