The `alpha`-D-glucose and `beta`-D-glucose isomers of glucose are known as .....

Options

A. enantiomers
B. stereoisomers
C. Anomers
D. glycomers

Answer

To answer the question regarding the isomers of glucose known as alpha-D-glucose and beta-D-glucose, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Isomers**:
- Isomers are compounds that have the same molecular formula but different structural arrangements. In the case of glucose, both alpha-D-glucose and beta-D-glucose have the same molecular formula (C6H12O6) but differ in the arrangement of atoms.

2. **Identifying the Structure of Glucose**:
- Glucose can exist in two cyclic forms: alpha (α) and beta (β). These forms are determined by the orientation of the hydroxyl group (-OH) attached to the first carbon atom (anomeric carbon) in the cyclic structure.

3. **Drawing the Structures**:
- For **alpha-D-glucose**:
- In the cyclic form, the -OH group on the first carbon (C1) is positioned below the plane of the ring.
- For **beta-D-glucose**:
- In the cyclic form, the -OH group on the first carbon (C1) is positioned above the plane of the ring.

4. **Defining Anomers**:
- The terms alpha and beta refer specifically to the configuration at the anomeric carbon (C1). Since they differ in the orientation of the -OH group at this carbon, they are classified as anomers.

5. **Conclusion**:
- Therefore, alpha-D-glucose and beta-D-glucose are known as **anomers** of glucose.

### Final Answer:
Alpha-D-glucose and beta-D-glucose are known as **anomers**.