Which of the following is a trisaccharide ?

Options

A. Stachyrose
B. Sucrose
C. Raffinose
D. Ribose

Answer

To determine which of the following options is a trisaccharide, we need to understand what a trisaccharide is. A trisaccharide is an oligosaccharide that consists of three monosaccharide units linked together by glycosidic bonds.

Let's analyze the options provided:

1. **Tachyrose**:
- Tachyrose is known to be a tetrasaccharide. It consists of two galactose units, one glucose unit, and one fructose unit. Since it has four monosaccharide units, it does not qualify as a trisaccharide.
- **Conclusion**: Tachyrose is not a trisaccharide.

2. **Sucrose**:
- Sucrose is composed of one glucose molecule and one fructose molecule. This means it consists of two monosaccharide units, making it a disaccharide.
- **Conclusion**: Sucrose is not a trisaccharide.

3. **Raffinose**:
- Raffinose is composed of three monosaccharide units: one galactose, one glucose, and one fructose. This means it qualifies as a trisaccharide.
- **Conclusion**: Raffinose is a trisaccharide.

4. **Ribose**:
- Ribose is a monosaccharide, which means it consists of only one sugar unit.
- **Conclusion**: Ribose is not a trisaccharide.

Based on this analysis, the only option that is a trisaccharide is **Raffinose**.

### Final Answer:
**Raffinose is the trisaccharide.**

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