Bacterial Cell Layers

A bacteria can have 1 to 4 layers

1. Plasma membrane: Found in all
2. Cell wall 1 aka Peptidoglycan: Found in all except L forms
3. Cell wall 2 aka Outer membrane: Found in gram negative bacteria only
   • Outer membrane is a Lipopolysaccharide (LPS) whose lipid A component can cause a toxic reaction when these bacteria are lysed by immune cells
4. Glycoclayx: Found in a select set of bacteria. Could be slime or Capsule ^90ed77
   • A distinct, gelatinous glycocalyx is called a Capsule
   • an irregular, diffuse layer is called a Slime layer

In other words

• Gram positive: Plasma membrane + Peptidoglycan
• Gram negative: Plasma membrane + Peptidoglycan + Outer membrane

See

• List of Gram Positive Bacteria
• List of Gram Negative Bacteria