Question

The lipopolysaccharide (LPS) possessed by Gram-negative bacteria contributes to the virulence and pathogenic potential of these organisms. The toxic portion of the LPS in ___________.
a. lipid A
b. located in the plasma membrane
c. a protein secreted by the bacterium
d. an antigenic polysaccharide
e. all of the above

Answer 1

Answer:

A. Lipid A

Explanation:

The outer membrane of Gram-negative bacteria is present outside to the thin peptidoglycan layer. The outer membrane consists of lipopolysaccharide (LPS) which is the molecule having both carbohydrates and lipids.

The lipopolysaccharide has three parts out of which lipid A is the toxin one. Lipid A is embedded in the outer membrane through its fatty acids. When lipid A enters the blood stream of the host cell, it leads to septic shock. Lipid A is heat stable and highly toxic.