Question:medium
Which of the following is true about endotoxin?
Which of the following is true about endotoxin?
Show Hint
Endotoxin is a lipopolysaccharide, not a protein enzyme, and is poorly antigenic.
Updated On: Jun 24, 2026
- Protein
- Highly antigenic
- No enzymatic activity
- Produced by gram positive bacteria
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Start from what endotoxin actually is. It is the lipopolysaccharide woven into the outer membrane of gram-negative organisms, with lipid A as the toxic moiety, and it is part of the cell wall rather than a secreted molecule.
Step 2: Since the molecule is a lipopolysaccharide and not a protein, it carries no enzyme function. It produces fever, hypotension, and shock by provoking host cytokines, not by catalysing any biochemical step, which makes statement (c) the true one.
Step 3: Testing the other claims: it is not a protein, so (a) fails; it is only weakly immunogenic, unlike the strongly antigenic exotoxins, so (b) fails; and it comes from gram-negative, never gram-positive, bacteria, so (d) fails.
Step 4: Remember too that endotoxin resists heat and cannot be detoxified into a toxoid, the opposite of the heat-sensitive exotoxins.
\[\boxed{\text{No enzymatic activity}}\]
Step 2: Since the molecule is a lipopolysaccharide and not a protein, it carries no enzyme function. It produces fever, hypotension, and shock by provoking host cytokines, not by catalysing any biochemical step, which makes statement (c) the true one.
Step 3: Testing the other claims: it is not a protein, so (a) fails; it is only weakly immunogenic, unlike the strongly antigenic exotoxins, so (b) fails; and it comes from gram-negative, never gram-positive, bacteria, so (d) fails.
Step 4: Remember too that endotoxin resists heat and cannot be detoxified into a toxoid, the opposite of the heat-sensitive exotoxins.
\[\boxed{\text{No enzymatic activity}}\]
Was this answer helpful?
0
