Which of the Following Statements Concerning Pairs of Sugars Is

Question

Which of the following statements concerning pairs of sugars is correct?
A)Glyceraldehyde and dihydroxyacetone are stereoisomers.
B)Glucose has fewer chiral centres than fructose.
C)Galactose and fructose are diastereomers.
D)Glucose and fructose are epimers.

Accepted Answer

Glyceraldehyde and dihydroxyacetone are not isomers in the traditional sense of having the same molecular formula but different structures; instead, they are structural isomers with different arrangements of their atoms. However, they are related as they both are simple sugars and can interconvert under certain conditions, but the correct term to describe their relationship is not "stereoisomers" because dihydroxyacetone lacks a chiral center, making the term inapplicable. The correct explanation is that glyceraldehyde has a chiral center, making it capable of existing as two enantiomers, while dihydroxyacetone does not have a chiral center and thus cannot exist as enantiomers or stereoisomers of glyceraldehyde.