Epimers of glucose ?
**Core Concept**
Glucose is a hexose sugar with a specific arrangement of hydroxyl (-OH) and hydrogen (H) atoms. Epimers are carbohydrates that differ in configuration at only one carbon atom. In the context of glucose, epimers are important for understanding the stereochemistry of sugar molecules.
**Why the Correct Answer is Right**
The epimers of glucose are mannose and galactose. These sugars differ in configuration at carbon-2 (C-2) of the glucose molecule. Mannose has an equatorial hydroxyl group at C-2, while galactose has an axial hydroxyl group at C-2. This difference in configuration affects the spatial arrangement of the sugar molecule and influences its interactions with enzymes and other molecules.
**Why Each Wrong Option is Incorrect**
* **Option A:** None provided, skipping to next option.
* **Option B:** Other epimers of glucose include allose and altrose, which differ in configuration at different carbon atoms (C-1 and C-3, respectively).
* **Option C:** Fructose is a ketohexose and not an epimer of glucose.
* **Option D:** None provided, skipping to next option.
**Clinical Pearl / High-Yield Fact**
When differentiating between epimers of glucose, remember that the configuration at C-2 is crucial. This is because many enzymes and receptors recognize and interact with glucose and its epimers through this specific carbon atom.
**Correct Answer:** A. Mannose and galactose.