prokaryotic cells

• prokaryotic cells

  = known as extremophiles- eg: hydrothermal vents and salt lakes now can live in soil and human digestive systems.

  • unicellular
• prokaryotic cells

  cell

  
• DNA

  = not contained within a nucleus, have 1 molecule of DNA (chromosome) which is supercoiled to make it more compact. The genes are grouped into operons, meaning some genes are switched on or off at the same time.
• ribosomes 


  smaller than eukaryotic cells. Size is determined by the rate at which they settle or form a sediment. 80s or 70s.
• cell wall 


  = made from peptidoglycan formed from amino acids+ sugars.
• flagella 


  = attached to the cell membrane of bacterium by a basal body and rotated by a molecular motor.

  • the energy to rotate the filament is supplied from the process of chemiosmosis.
  • basal body attaches to filament comprising the flagellum to the cell-surface membrane.
  • molecular motor cause hook to rotate giving the filament a whip like movement which propels the cell.