Which of the following is a heteropolysaccharide?

Options

A. Peptidoglycan
B. Chitin
C. Cellulose
D. Starch

Answer

To determine which of the following is a heteropolysaccharide, we need to understand the classification of polysaccharides based on their composition.

### Step-by-Step Solution:

1. **Understand Polysaccharides**: Polysaccharides are large molecules made up of sugar units (monomers). They can be classified into two main types based on their composition: homopolysaccharides and heteropolysaccharides.

2. **Define Heteropolysaccharides**: Heteropolysaccharides are polysaccharides that consist of more than one type of monomer. This means they are made up of different kinds of sugar units.

3. **Define Homopolysaccharides**: In contrast, homopolysaccharides are made up of only one type of monomer. Examples include starch, cellulose, and chitin.

4. **Analyze the Given Options**: The options provided are:
- Chitin
- Cellulose
- Starch
- Peptidoglycan

5. **Identify Homopolysaccharides**:
- **Chitin**: A homopolysaccharide made up of N-acetylglucosamine units.
- **Cellulose**: A homopolysaccharide made up of glucose units.
- **Starch**: A homopolysaccharide made up of glucose units.

6. **Identify Heteropolysaccharides**:
- **Peptidoglycan**: This is a heteropolysaccharide composed of various sugar units (N-acetylglucosamine and N-acetylmuramic acid) and is found in the cell walls of bacteria.

7. **Conclusion**: Among the options provided, the only heteropolysaccharide is **peptidoglycan**.

### Final Answer:
The heteropolysaccharide among the options is **peptidoglycan**.

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