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:

1. Glucose – found free in fruits and vegetables
2. Fructose – found free in fruits and in bee honey
3. 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

1. They are soluble in water
2. They are crystallisable
3. They are sweet
4. The are all reducing sugars
5. 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

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