-Which structure(s)shown in the figure above represent reducing sugar(s)?
A)A
B)D
C)C and D
D)A,B,C,and D
E)A,B,and C

Question

-Which structure(s)shown in the figure above represent reducing sugar(s)?
A)A 
B)D 
C)C and D 
D)A,B,C,and D 
E)A,B,and C

Quizplus · Accepted Answer

Reducing sugars are those that have a free aldehyde group or a free ketone group that can act as a reducing agent. Structures A, B, and C each have a free anomeric carbon that can open to form an aldehyde or ketone, making them capable of reducing other chemicals, hence they are considered reducing sugars. Structure D, on the other hand, does not have a free anomeric carbon because it is involved in a glycosidic bond, preventing it from opening into an aldehyde or ketone form, thus it is not a reducing sugar.

-Which Structure(s)shown in the Figure Above Represent Reducing Sugar(s)