Plasma membrane of bacteria

• Contain two layers and is made up of peptides, protein and carbohydrate.
• Inner membrane :- permeability barrier.
• Outer membrane and cell wall: provides protection to the cell.
• Space between two membrane is called periplasm.

Cell wall of bacteria

• Protect cell from mechanical injury and osmotic pressure.
• Is 3-25 nm thick.
• Composed of peptidoglycan, a complex of oligosaccharides and protein.
• Oligosaccharides consists of long chain of alternating N-acetyl glucosamine (Glc NAC) and N-acetyl muramic acid (NAM) linked by β ( 1à 4) bond.
• Circular segment of DNA in cytoplasm is called plasmid.
• Cell wall of gram-negative bacteria Staphylococcs aureus is made up of N-acetyl glucosamine covalently bonded with N-acetyl muramic acid by β ( 1à 4)-O- glycosidic bond.
• Cell wall of gram-negative bacteria is absent of pentaglycine and teichonic acid.