Question

The structure of D-(+)-glucose is given. The structure of L-(-)glucose is

Answer 1

Carbohydrates are one of the classes of biomolecules with general formula is ${{\text{C}}_{\text{x}}}{\left( {{{\text{H}}_{\text{2}}}{\text{O}}} \right)_{\text{y}}}$ where x and y may be the same or different.The carbohydrates are further classified as monosaccharides, disaccharides, oligosaccharides, and polysaccharides depending on the units from which they are formed.
Glucose is a carbohydrate with having chemical formula is ${{\text{C}}_{\text{6}}}{{\text{H}}_{{\text{12}}}}{{\text{O}}_{\text{6}}}$. It contains aldehyde and hydroxyl groups.

Complete answer:
In the case of the D sugar molecule, the ${\text{ - OH}}$group of the lowest chiral center is on the right side while in the case of the L sugar ${\text{ - OH}}$group of the lowest chiral center is on the left side of the Fischer projection formulae.
Here, two sugar molecules are different in their sign. The + and – signs indicate these two sugar molecules rotate the plane of plane polarised light in different directions.
It means D-(+)-glucose and L-(-)glucose are enantiomers hence, they are mirror images of each other.
Here, the structure of the D-(-)glucose and its mirror image is as follows:

Here, in option(B) structure given is not a mirror image of the given D-(+)-glucose molecule hence, it is an incorrect answer.
Here, in option(C) structure given is not a mirror image of the given D-(+)-glucose molecule hence, it is an incorrect answer.
Here, in option(D) structure given is not a mirror image of the given D-(+)-glucose molecule hence, it is an incorrect answer.
Therefore, option (A) is the correct answer to the question.

Note: Fischer projection two-dimensional representation used to represent the sugar molecules. In Fischer's projection, the position of the${\text{ - OH}}$ group decides whether it is D or L sugar.
Stereoisomers are the isomers having the same chemical formula but different arrangements of groups in space.Enantiomers are the stereoisomers which are mirror images of each that rotate the plane of plane-polarized light in the opposite direction.