Monosaccharides

Monosaccharides are monomers

Monosaccharides can be classified by the number of carbons they possess

Three-carbon sugars = trioses

Five-carbon sugars = pentoses (deoxyribose, ribose)

Six-carbon sugars = hexoses (glucose, galactose, fructose)

Features:

• Mostly ring structures

• One C-atoms is usually outside the ring

• All attached to -OH groups

• Atoms C,H,O are in the ratio of 1:2:1

Function:

• Easily transported in the blood dissolving in the plasma

• Useful for food storage

• Stored in large quantities in cells would lead to osmotic problems

• Transfers and stores energy

• Builds more complex molecules

Glucose has two isomers: alpha (a) D-Glucose and beta (B) D-Glucose

Same molecular form

Glucose is polar and hydrophilic and is soluble in aqueous solution

Monosaccharides have strong covalent bonds and therefore are very stable

Glucose gives out energy when oxidised during cellular respiration