Functions of lipopolysaccharides in bacterial cells?

1. Structural integrity: Lipopolysaccharides (LPS) are major components of the outer membrane of Gram-negative bacteria and play a crucial role in maintaining the structural integrity of the cell envelope.

2. Protection: LPS acts as a barrier against harmful substances such as antibiotics, detergents, and host immune defenses, protecting the bacterial cell from external threats.

3. Recognition: LPS is recognized by the host immune system as a pathogen-associated molecular pattern (PAMP), triggering an immune response against the invading bacteria.

4. Endotoxin activity: The lipid A component of LPS is responsible for the endotoxin activity of Gram-negative bacteria, which can cause severe inflammatory responses and septic shock in the host.

5. Biofilm formation: LPS can also play a role in biofilm formation, a protective mechanism used by bacteria to adhere to surfaces and resist environmental stresses.

6. Cell signaling: LPS can interact with host cells and trigger signaling pathways that modulate immune responses, inflammation, and other cellular processes.