Peptidoglycan present in bacterial cell envelope is

Options

A. Made up of cellulose
B. A heteropolymer
C. An oligosaccharide
D. A homopolymer

Answer

### Step-by-Step Solution:

1. **Understanding Peptidoglycan**: Peptidoglycan is a crucial component of the bacterial cell envelope. It provides structural support and shape to the bacterial cell.

2. **Composition of Peptidoglycan**: Peptidoglycan is composed of two main components:
- **Sugars**: Specifically, it contains two types of sugar molecules:
- N-acetylglucosamine (NAG)
- N-acetylmuramic acid (NAM)
- **Amino Acids**: In addition to sugars, peptidoglycan also contains amino acids that form cross-links between the sugar chains.

3. **Classification of Peptidoglycan**: Given the presence of different types of molecules (sugars and amino acids), peptidoglycan is classified as a **heteropolymer**. This means it is made up of different types of monomers (in this case, sugars and amino acids).

4. **Evaluating Options**:
- **Cellulose**: Incorrect, as cellulose is a homopolymer of glucose and not part of peptidoglycan.
- **Oligosaccharide**: Incorrect, as peptidoglycan is not just a short chain of sugars; it also includes amino acids.
- **Homopolymer**: Incorrect, since peptidoglycan contains different types of molecules (sugars and amino acids), making it a heteropolymer.

5. **Conclusion**: The correct classification of peptidoglycan in the bacterial cell envelope is that it is a **heteropolymer** composed of sugars and amino acids.