Carbohydrates

• Monosaccharides are the monomers from which larger carbohydrates are made.
• A condensation reaction between two monosaccharides forms a glycosidic bond.
• Maltose = a-glucose + a-glucose
• Sucrose = a-glucose + fructose
• Lactose = a-glucose + galactose
• Polysaccharides are formed by the condensation of many glucose units.
• Glycogen and starch are formed by the condensation of a-glucose.
• Cellulose is formed by the condensation of b-glucose.
• To test for reducing sugar you add Benedict’s reagent and gently boiled water. If present orangy-red colour will show.
• To test for non-reducing sugar you add Benedict's reagent and gently boiled water. If nothing happens then add acid and gently boil. Neutralise with sodium bicarbonate and then test with ph paper. Retest with benedicts solution