Outer membrane

Outer Membrane

The outer membrane is a distinctive feature of Gram-negative bacteria, which forms a barrier and protects the bacteria from several types of antibiotics, dyes, and detergents that would otherwise damage the cell. It also plays a key role in the pathogenesis of many bacteria.

Structure

The outer membrane of the Gram-negative bacteria differ from other prokaryotes due to its unique lipid composition. It is composed of lipopolysaccharides (LPS), phospholipids, and lipoproteins. The LPS layer is an endotoxin and can trigger a strong immune response.

Function

The outer membrane serves as a protective barrier for the bacteria. It prevents the entry of several harmful substances including certain antibiotics, lysozyme, and detergents which would otherwise prove harmful to the bacteria.

Role in Pathogenesis

The outer membrane plays a significant role in the pathogenesis of the bacteria. The LPS layer can trigger a strong immune response during bacterial infections. Some bacteria can alter the structure of their outer membrane to evade the immune system.

See Also

• Cell membrane
• Gram-negative bacteria
• Lipopolysaccharide
• Pathogenesis