Glucose and Mannose: Epimers

Introduction:
Glucose and mannose are monosaccharides, which are the simplest form of carbohydrates. They are both hexoses, meaning they have six carbon atoms in their structure. These two sugars are stereoisomers of each other, specifically epimers, due to the difference in the spatial arrangement of one carbon atom.

Epimers:
Epimers are a type of stereoisomers that differ in the configuration around only one carbon atom. In the case of glucose and mannose, the difference lies in the configuration around the second carbon atom (C2).

Structural Difference:
Glucose and mannose have the same molecular formula (C6H12O6), but their arrangement of atoms differs at the second carbon atom. In glucose, the hydroxyl (OH) group and the hydrogen (H) atom at C2 are on the same side of the molecule, referred to as the alpha configuration. In mannose, however, the hydroxyl and hydrogen group are on opposite sides of the molecule, known as the beta configuration.

Isomeric Relationship:
Glucose and mannose are isomers of each other. Isomers are compounds that have the same molecular formula but different structural arrangements. In the case of glucose and mannose, they are specifically epimers since they differ in the configuration of only one carbon atom.

Functional Groups:
Both glucose and mannose are classified as keto-hexoses. Keto-hexoses are hexoses that contain a ketone functional group (C=O) on their structure. Glucose and mannose both have a ketone group located at the second carbon atom.

Conclusion:
In summary, glucose and mannose are epimers of each other. They have the same molecular formula and are classified as keto-hexoses. The difference between them lies in the spatial arrangement around the second carbon atom. Glucose has an alpha configuration, while mannose has a beta configuration at C2.