Question

What is the structural feature characterising reducing sugar?

Answer 1

Those carbohydrates which contain free aldehyde or ketonic group reduce Fehling's solutions and Tollen's reagent are called reducing sugar e.g., monosaccharides like glucose, fructose, galactose are reducing sugars.

Answer 2

Explanation:

The main structural feature of reducing sugars is the presence of an aldehyde group (-CO) such as in glucose, mannose, galactose , etc. . Or the α -ketol grouping (-CO-CH2OH) as present in fructose.