Which one of the following is a polysaccharide?

Options

A. Glucose
B. Glycogen
C. Maltose
D. Lactose

Explanation

To determine which of the given options is a polysaccharide, we need to understand the definitions and characteristics of polysaccharides, monosaccharides, and disaccharides.

### Step-by-Step Solution:

1. **Understand the Definition of Polysaccharides**:
- Polysaccharides are large molecules made up of many smaller units called monosaccharides. They can be classified into two types:
- Homopolysaccharides (composed of one type of monosaccharide)
- Heteropolysaccharides (composed of two or more types of monosaccharides).

2. **Analyze the Options**:
- **Option 1: Glucose**
- Glucose is a monosaccharide, which means it is a simple sugar and not a polysaccharide.
- **Option 2: Glycogen**
- Glycogen is a polysaccharide. It is made up of many glucose units and serves as a form of energy storage in animals, fungi, and bacteria.
- **Option 3: Maltose**
- Maltose is a disaccharide, which means it is composed of two monosaccharide units (specifically two glucose units).
- **Option 4: Lactose**
- Lactose is also a disaccharide, made up of two different monosaccharides: glucose and galactose.

3. **Identify the Polysaccharide**:
- Among the options provided, glycogen is the only one that fits the definition of a polysaccharide, as it is composed of multiple glucose units.

### Conclusion:
The correct answer is **Option 2: Glycogen**, which is a polysaccharide.

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