Carbohydrates are classified on the basis of their bahaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is a ............ .

Options

A. monosaccharide
B. disaccharide
C. reducing sugar
D. non-reducing sugar

Explanation

To answer the question regarding the classification of sucrose, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Carbohydrate Classification**: Carbohydrates are classified based on their behavior during hydrolysis and whether they are reducing or non-reducing sugars.

2. **Identify Sucrose**: Sucrose is a common carbohydrate known as table sugar. It is important to determine its classification.

3. **Hydrolysis of Sucrose**: When sucrose undergoes hydrolysis, it breaks down into two monosaccharides: glucose and fructose. This reaction can be represented as:
\[ \text{Sucrose} \xrightarrow{\text{H}_2\text{O}} \text{Glucose} + \text{Fructose} \]

4. **Determine the Type of Carbohydrate**: Since sucrose is made up of two monosaccharides (glucose and fructose), it is classified as a disaccharide.

5. **Reducing vs Non-reducing Sugar**: Reducing sugars are those that can donate electrons to reduce other molecules. In the case of sucrose, the reducing groups of glucose and fructose are involved in the glycosidic bond formation. This means that they cannot act as reducing agents.

6. **Conclusion**: Therefore, sucrose is classified as a non-reducing sugar because it does not have a free aldehyde or ketone group available to participate in reduction reactions.

### Final Answer:
Sucrose is a **non-reducing sugar**.

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