Which of the following is reducing sugar ?

Options

A. Glucinol
B. Galactose
C. `beta`- galactosidase
D. None of these

Answer

To determine which of the following is a reducing sugar, we need to understand what a reducing sugar is and analyze the given options: glucinol, galactose, beta-galactosidase, and none of these.

### Step-by-Step Solution:

1. **Definition of Reducing Sugar**:
A reducing sugar is a carbohydrate that has a free aldehyde or ketone group. This functional group allows the sugar to reduce other compounds, such as copper ions (Cu²⁺), to their elemental form (Cu).

2. **Identifying the Functional Groups**:
- **Glucinol**: This is a sugar alcohol derived from glucose and does not have a free aldehyde or ketone group.
- **Galactose**: This is a monosaccharide that contains a free aldehyde group, which makes it a reducing sugar.
- **Beta-galactosidase**: This is an enzyme that catalyzes the hydrolysis of beta-galactosides and is not a sugar itself.
- **None of these**: This option suggests that none of the provided options are reducing sugars.

3. **Analyzing the Options**:
- Glucinol is not a reducing sugar.
- Galactose is a reducing sugar due to its free aldehyde group.
- Beta-galactosidase is not a sugar.
- Therefore, the option "none of these" is incorrect.

4. **Conclusion**:
Based on the analysis, the only reducing sugar among the options provided is **galactose**.

### Final Answer:
Galactose is the reducing sugar.

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