Prokaryotic Cells

• Cell wall


  • Rigid outer covering made of peptidoglycan
  • Provides the cell with strength and support
• Slime capsule


  • Protective slimy layer
  • Helps the cell to retain moisture
  • Helps the cell adhere to surfaces
• Plasmid


  Circular pieces of DNA
• Flagellum


  • Tail-like structure
  • Rotates to move the cell
• Pili


  • Hair-like structures
  • Attach to other bacterial cells
  • Allow exchange of plasmids
• 70S Ribosomes


  • Composed of two subunits
  • Site of protein synthesis
• Mesosomes


  • Infoldings of the inner membrane
  • Function is debated
  • Some believe they are just artefacts from microscopy preparation
  • Others believe they contain enzymes required for respiration