Lipopolysaccharide (LPS) is a component of:

A Gram-positive cell wall

B The outer membrane of gram-negative bacteria, acting as an endotoxin

C Viral capsid

D Fungal cell wall

✓ Correct Answer: Option B

LPS: component of gram-negative outer membrane (Lipid A = toxic moiety). Activates TLR4 → macrophage/monocyte activation → TNF-α, IL-1, IL-6 release. Causes septic shock in high concentrations.

💡 Why is B) the correct answer?

The correct answer to the question "Lipopolysaccharide (LPS) is a component of:" is Option B: The outer membrane of gram-negative bacteria, acting as an endotoxin.

The other options — A) Gram-positive cell wall, C) Viral capsid, D) Fungal cell wall — are incorrect for this USMLE Exam Prep question. As explained above: LPS: component of gram-negative outer membrane (Lipid A = toxic moiety). Activates TLR4 → macrophage/monocyte activation → TNF-α, IL-1, IL-6 release. Causes septic shock in high concentrations.

📚 About This USMLE Exam Prep Practice Question

This 2-level USMLE Exam Prep question from the Step 1 - Basic Sciences topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free USMLE Exam Prep practice test or use flashcards for spaced repetition review.

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Lipopolysaccharide (LPS) is a component of:

✓ Correct Answer: Option B

📚 About This USMLE Exam Prep Practice Question

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