MONOSACCHARIDES

• These are simple sugars
• The carbon atoms in these sugars form a chain to which hydrogen and oxygen atoms are attached
• Monosaccharides are classified according to the number of carbon atoms they possess
• The most common monosaccharides are:
• Glucose – found free in fruits and vegetables
• Fructose – found free in fruits and in bee honey
• Galactose – found combined in milk sugar
• The general formula for these monosaccharides is (CH2O)n where n is 6
• They have the same number of carbon, hydrogen and oxygen molecules i.e C6H12O6

Properties of Monosaccharides

• They are soluble in water
• They are crystallisable
• They are sweet
• The are all reducing sugars
• This is because they reduce blue copper (II) sulphate solution when heated to copper oxide which is red in colour and insoluble

Functions of Monosaccharides

• They are oxidised in the cells to produce energy during respiration
• Formation of important biological molecules e.g. deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
• Some monosaccharides are important metabolic intermediates e.g. in photosynthesis and in respiration
• Monosaccharides are the units from which other more complex sugars are formed through condensation

Also See:

PROCESS OF PHOTOSYNTHESIS

NUTRITION IN PLANTS

BIOLOGY PRACTICAL

ACTIVE TRANSPORT

WATER RELATIONS IN PLANT AND ANIMAL CELLS