identifying reducing sugars. help

[Simmy]

i just did a lab in biology to identify Reducing Sugars. as a result Sucrose was not a identified by this lad.

can any one explain to me why Sucrose was not identified by the reducing sugars lab?????

Is sucrose not a reducing sugar?????

[Navin]

Yes, sucrose is not a reducing sugar and therefore cannot be identified by benedict's test for reducing sugars.

[MrMistery]

Occam's raiser: the simplest explanation is often the right one

[sdekivit]

i just did a lab in biology to identify Reducing Sugars. as a result Sucrose was not a identified by this lad.

can any one explain to me why Sucrose was not identified by the reducing sugars lab?????

Is sucrose not a reducing sugar?????

fructose doesn't contain a so called hemi-acetal group and has therefore no reducing power.

compare with for example glucose, it contains a O - CHOH-group at the anomer C-atom (C1), which is in equilibrium with the open chain form. The open chainform is an aldehyde group that can reduce compunds and is thereby converted to a carboxylgroup.

--> the open chain form of fructose is a ketone-group that hasn't got reducing power (only oxidizing)