Cell wall 1

• Prokaryotic cells


  Cells where the hereditary material called DNA is not enclosed in a membrane and there is no internal structure like nucleus
• Prokaryotic cell refers to bacteria and blue green algae cells
• The absence of intracellular organelles indicates primitive nature of prokaryotic cells
• Prokaryotes is the term given to organisms without true nucleus (pro, before; karyon, nucleus)
• Structure of a generalized bacterium, a typical prokaryotic cell

  • Capsules and slime layers
  • Cell wall
  • Cell membrane
  • Cytoplasm
  • DNA
  • Ribosomes
  • Flagellum
• Capsules


  Comparatively thicker and more compact than slime layers
• Slime layers


  Diffused and more or less compact
• Functions of capsules and slime layers

  • Give additional protection to the bacteria from unfavourable conditions
  • Enable the bacteria to stick to each other and form colonies
  • Enable the bacteria to stick to the surface of food supply or host cell
• The presence of capsule is an indication of virulence of some bacteria