Fungal wall composition: In the cell walls of a mushroom (a basidiomycete), how does the amount of peptidoglycan compare with the amount of chitin?

Introduction / Context:Cell wall chemistry distinguishes fungal cells from bacterial cells. Mushrooms (basidiomycetes) exemplify the classic fungal wall composed primarily of chitin and glucans, whereas peptidoglycan is a hallmark of most bacteria.

Given Data / Assumptions:

• Mushrooms are true fungi, not bacteria.
• Peptidoglycan is typical of bacterial walls; chitin is typical of fungal walls.
• Comparison seeks relative amounts within mushroom cell walls.

Concept / Approach:Fungal walls contain chitin microfibrils embedded in a matrix of beta-glucans and mannoproteins. Peptidoglycan (murein) is absent from fungal walls; its presence is a defining bacterial feature (with exceptions like Mycoplasma lacking walls). Therefore, the amount of peptidoglycan in mushrooms is negligible or absent, far less than chitin.

Step-by-Step Solution: Identify the principal polymer in fungal walls: chitin. Recognize that peptidoglycan is a bacterial, not fungal, structure. Conclude that peptidoglycan is essentially absent, hence far less than chitin. Select the option stating it is lesser than chitin.

Verification / Alternative check:Antibacterial beta-lactams target peptidoglycan synthesis and are ineffective against fungi, whereas antifungals target ergosterol or beta-glucan pathways, reinforcing the compositional difference.

Why Other Options Are Wrong:

• Greater or equal amounts contradict fundamental fungal biology.
• Peptidoglycan replaces chitin: Incorrect; chitin remains central.
• None of the above: Unnecessary since one statement is correct.

Common Pitfalls:Conflating bacterial and fungal wall components due to both being “walled” organisms.

Final Answer:It is lesser than the amount of chitin (essentially absent peptidoglycan).