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:
WATER RELATIONS IN PLANT AND ANIMAL CELLS