DISACCHARIDES – WELL EXPLAINED

These contain two monosaccharide units. The chemical process through which a large molecule (e.g a disaccharide) is formed from smaller molecules is called condensation and it involves loss of water

Common examples of disaccharides include sucrose, maltose and lactose

1. Disaccharides are broken into their monosaccharide units by heating with dilute hydrochloric acid
2. This is known as hydrolysis and involves addition of water molecules
3. The same process takes place inside cells through enzymes

Sucrose + water = hydrolysis—————–glucose+fructose Properties of Disaccharides

• Sweet tasting
• Soluble in water
• Crystallisable
• Maltose and lactose are reducing sugars while sucrose is non-reducing sugar
• Sucrose is the form in which carbohydrate is transported in plants:
• This is because it is soluble andjchernically stable
• Sucrose is a storage carbohydrate in some plants e.g sugar-cane and sugar-beet
• Disaccharides are hydrolysed to produce monosaccharide units which are readily metabolised by cell to provide energy.

Also See:

PROCESS OF PHOTOSYNTHESIS

NUTRITION IN PLANTS

BIOLOGY PRACTICAL

ACTIVE TRANSPORT

WATER RELATIONS IN PLANT AND ANIMAL CELLS