8 What is a reducing sugar and how would you determine if it

8). What is a reducing sugar and how would you determine if it is present in a mixture of unknown? What color change would you expect to observe? Brick red, purple or black I have a biology lab exam coming up this is one of the review topic questions. I would appreciate the help.

Solution

Reducing sugars are the sugars that have free aldehyde or ketone group. Reducing sugar upon oxidation convert into the carboxylic acid.

when reducing sugar react with Benedicts reagent (CuSO₄ / citrate) or Fehlings reagent (CuSO₄ / tartrate) they give red colour because they convert Cu2+ into Cu+