1,4 glycosidic bond
Glycosidic bonds are formed due to condensation reactions between a hydroxyl residue on carbon-1 and the anomeric carbon-4 on two monosaccharides (monomers, single units of sugar), to form a disaccharide ( 2 monomers bound together) and subsequently a polysaccharide (polymers, or many units of sugars). A condensation reaction is when water is eliminated to form a simple molecule. Later hydrolysis by water molecules will reform the two original monosaccharides.
The 1,4 glycosidic bond is formed between the carbon-1 of one monosaccharide and carbon-4 of the other monosaccharide. There are are two types of glycosidic bonds - 1,4 alpha and 1,4 beta glycosidic bonds. 1,4 alpha glycosidic bonds are formed when the OH on the carbon-1 is below the glucose ring; while 1,4 beta glycosidic bonds are formed when the OH is above the plane[1]. When two alpha D-glucose molecules join together a more commonly occurring isomer of glucose compared to the L-glucose, form a glycosidic linkage, the term is known as a α-1,4-glycosidic bond[2].
=== References ===
- ↑ Jeremy M. Berg, John L. Tymoczko, Lubert Stryer . Biochemistry Seventh Edition Freeman
- ↑ Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Section 11.2, Complex Carbohydrates Are Formed by Linkage of Monosaccharides. Available from: http://www.ncbi.nlm.nih.gov/books/NBK22396/