Sucrose is not a reducing sugar since

Options

A. It is chemically stable
B. it contains no free aldehyde or keto group adjacent to a gtCHOH group
C. It is built up of a fructose unit
D. it is optically active

Answer

**Step-by-Step Solution:**

1. **Understanding Sucrose Structure**: Sucrose is a disaccharide composed of two monosaccharides: glucose and fructose.

2. **Identifying Functional Groups**: Reducing sugars are characterized by the presence of free aldehyde or ketone functional groups. In sucrose, both glucose and fructose are linked together through a glycosidic bond.

3. **Glycosidic Bond Formation**: The glycosidic bond in sucrose is formed between the anomeric carbon of glucose and the anomeric carbon of fructose. This linkage prevents the aldehyde group of glucose and the ketone group of fructose from being free.

4. **Conclusion on Reducing Ability**: Since sucrose does not have a free aldehyde or ketone group due to the glycosidic bond, it cannot act as a reducing agent. Therefore, sucrose is classified as a non-reducing sugar.

5. **Final Statement**: In summary, sucrose is not a reducing sugar because it lacks the necessary functional groups (aldehyde or ketone) that would allow it to participate in reduction reactions.

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