Reducing sugar question

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Can someone explain how to tell if a sugar is reducing or non reducing?

 

[Anemone]

Can someone explain how to tell if a sugar is reducing or non reducing?

In basic solution if it makes CHO or ketones,then its reducing. Non-reducing sugars like sucrose dont have that free OH at the anomeric carbon to react.

Benedicts tests for reducing sugars.

 

[Dotoday]

Yes the reducing sugar such as Glucose has an aldehyde group in the open conformation and a hemiacetal group in a closed conformation. Due to the esposure of its aldehyde (CHO) group in the open conformation Glucose reacts positively with Tollens reagent and the Bennedict's solution. Sucrose on the other hand is nonreducing because it has no CHO exposed and therefore has no Hemiacetal group. Therefore it does not react with tollens or benedicts.
I hope this Helps,
Good luck studying.