What structural component is present in the outer membrane of Gram-negative bacterial cell walls and acts as an endotoxin triggering septic shock?
Answer and explanation
Correct answer: A. Lipopolysaccharide (LPS) containing toxic Lipid A
- Step 1: Gram-negative bacteria have an asymmetric outer membrane outside a thin peptidoglycan layer. Step 2. The outer leaflet consists of lipopolysaccharide (LPS). Lipid A is the toxic moiety recognized by Toll-like receptor 4 (TLR4), triggering systemic cytokine release. Answer: Lipopolysaccharide (LPS) containing toxic Lipid A. Why not the others: Teichoic acid is characteristic of Gram-positive walls; dipicolinic acid is found in bacterial endospores.
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