Lipopolysaccharide

Definition

Lipopolysaccharide (LPS) is a major component of the outer membrane of Gram-negative bacteria. It acts as an endotoxin and can trigger strong immune responses in humans.

5 Must Know Facts For Your Next Test

1. LPS is found in the outer membrane of Gram-negative bacteria such as Escherichia coli and Salmonella.
2. LPS consists of three parts: lipid A, core polysaccharide, and O-antigen.
3. The lipid A component is responsible for the toxic effects associated with LPS.
4. LPS can cause septic shock if it enters the bloodstream in significant amounts.
5. Detection of LPS in clinical samples can indicate a bacterial infection, especially in gastrointestinal diseases.

Review Questions

• What are the three components of lipopolysaccharide?
• How does lipopolysaccharide contribute to septic shock?
• Why is lipopolysaccharide significant in diagnosing bacterial infections?

Related terms

Endotoxin: A toxin that is released when bacteria disintegrate, commonly associated with the outer membrane of Gram-negative bacteria.

Gram-negative Bacteria: Bacteria characterized by a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Septic Shock: A severe medical condition resulting from an overwhelming immune response to infection, often linked to endotoxins like LPS.