The `alpha - D - ` glucose and `beta- D - ` glucose differ from each other at one of the carbon atom due to difference in

Options

A. Number of OH groups
B. Size of hemiacetal ring
C. Conformation
D. Configuration

Answer

To solve the question regarding the difference between alpha-D-glucose and beta-D-glucose, we need to understand the structural differences between these two forms of glucose.

### Step-by-Step Solution:

1. **Understanding the Structure of Glucose**:
- Glucose is a six-carbon sugar (hexose) with the molecular formula C6H12O6. It has multiple hydroxyl (OH) groups attached to its carbon atoms.

2. **Identifying the Anomeric Carbon**:
- In glucose, the first carbon (C1) is known as the anomeric carbon. This is the carbon that is involved in the formation of the cyclic structure of glucose.

3. **Formation of Cyclic Structures**:
- When glucose cyclizes, the hydroxyl group on the fifth carbon (C5) attacks the carbonyl group (C=O) on the first carbon (C1), leading to the formation of a hemiacetal.

4. **Differentiating Alpha and Beta Forms**:
- In the cyclic form of glucose, the orientation of the hydroxyl group (OH) attached to the anomeric carbon (C1) determines whether it is alpha or beta:
- **Alpha-D-Glucose**: The hydroxyl group on C1 is positioned on the **right** side of the ring structure.
- **Beta-D-Glucose**: The hydroxyl group on C1 is positioned on the **left** side of the ring structure.

5. **Conclusion**:
- Therefore, alpha-D-glucose and beta-D-glucose differ from each other at the configuration of the anomeric carbon (C1). This difference in configuration leads to the two distinct forms of glucose.

### Final Answer:
The alpha-D-glucose and beta-D-glucose differ from each other at one of the carbon atoms due to differences in their **configuration** at the anomeric carbon (C1).