Question

Which is correct for the structure of the cell wall of bacteria and fungi?
A. Both are made up of cellulose
B. Both have mucopeptide
C. Both are made up of N-acetylglucosamine
D. None of these

Answer 1

The bacterial cell wall is made up of peptidoglycans and GlcNAc chains. On the other hand, the cell walls of fungi are made up of chitin and linked chains of GlcNAc.

Complete answer: The cell wall is the outermost layer of prokaryotic or fungal cells. It lies above the plasma membrane. It acts as a filtering membrane. GlcNAc is an amide derivative of the monosaccharide glucose. It is considered secondary amide and is found in fungal and bacterial cell walls. It is another name for N-acetylglucosamine.

Option A: The cell walls of both bacteria and fungi are made of cellulose. Cellulose is the building block for plant cell walls. It is not a component of either bacterial or fungal cell walls.
Option B: It states that the cell walls of both bacteria and fungi are made up of mucopeptide. It is peptidoglycan composed of polysaccharides and peptide chains. It is peptidoglycan, it is found in bacterial cell walls. But it is not present in fungal cell walls.
Option C: Both bacterial and fungal cell walls are composed of N-acetylglucosamine or GlcNAc. Although the bacterial cell wall contains peptidoglycans as their main unit of the cell wall, they do contain some N-acetylglucosamine. The cell walls of fungi are made of chitin mainly, but also contain chains of N-acetylglucosamine. Thus, N-acetylglucosamine is common in both cell wall structures.
Hence option C is correct.

Note: The cell walls provide shape and structure to the cells. But another major function of cell walls in prokaryotes and fungi is to regulate the expansion of cell walls when water enters inside the cell. The chemical composition of cell walls provides characteristic features to bacterial and fungal cell walls. And these characteristics are used to identify different types of microbes.