CIE A Level Biology复习笔记2.2.3 Reducing & Non-Reducing Sugars

• Sugars can be classified as reducing or non-reducing; this classification is dependent on their ability to donate electrons
• Reducing sugars can donate electrons (the carbonyl group becomes oxidised), the sugars become the reducing agent
  • Thus reducing sugars can be detected using the Benedict’s test as they reduce the soluble copper sulphate to insoluble brick-red copper oxide
  • Examples: glucose, fructose, maltose
• Non-reducing sugars cannot donate electrons, therefore they cannot be oxidised
  • To be detected non-reducing sugars must first be hydrolysed to break the disaccharide into its two monosaccharides before a Benedict’s test can be carried out
  • Example: sucrose

The mnemonic to remember the definitions for oxidation and reduction