Which of the following disaccharide consists only of glucose unit?

Options

A. Sucrose
B. Maltose
C. Lactose
D. All of these

Answer

To solve the question "Which of the following disaccharides consists only of glucose units?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Disaccharides**: Disaccharides are carbohydrates formed by the combination of two monosaccharide units. We need to identify which disaccharide is made up entirely of glucose.

2. **Analyzing Sucrose**:
- Sucrose is composed of two different monosaccharides: alpha-D-glucose and beta-D-fructose.
- When sucrose undergoes hydrolysis, it breaks down into these two monosaccharides.
- Since it contains fructose, it does not consist only of glucose units.
- **Conclusion**: Sucrose is not our answer.

3. **Analyzing Maltose**:
- Maltose is formed by the combination of two alpha-D-glucose units.
- When maltose is hydrolyzed, it yields two molecules of alpha-D-glucose.
- Since both units are glucose, maltose consists entirely of glucose units.
- **Conclusion**: Maltose is a potential answer.

4. **Analyzing Lactose**:
- Lactose is made up of two different monosaccharides: beta-D-galactose and beta-D-glucose.
- Upon hydrolysis, lactose breaks down into these two units.
- Since it contains galactose, it does not consist only of glucose units.
- **Conclusion**: Lactose is not our answer.

5. **Final Conclusion**:
- After analyzing all the options, we find that only maltose consists solely of glucose units.
- Therefore, the correct answer is **maltose**.

### Answer: Maltose (Option 2)

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