Which of the following carbohydrates act as reducing sugars in alkaline medium? — Biomolecules Chemistry Question

💡 Solution & Explanation

Sugars with a free hemiacetal or hemiketal group can open into an aldehyde/ketone and reduce Tollens' or Fehling's reagents. Fructose, despite being a ketose, isomerizes to an aldose in base. Sucrose has an acetal linkage blocking both anomeric carbons and is non-reducing.