Prokaryotic cells & viruses

• Circular DNA (Bacteria)

  Possesses genetic information for replication of cells
• Capsules (Bacteria)

  Protects bacteria from other cells

  Helps groups of bacteria stick together
• Plasmid (Bacteria)

  Possesses genes that may aid survival of bacteria

  Can reproduce independently
• Mesosome (Bacteria)

  Specialised in fold region of the cell membrane, involved in aerobic respiration.

  ATP is made here
• Cell Wall (Bacteria)

  Mechanical protection

  Made of murein
• Pili (Bacteria)

  For attachment to other cells

  Role in reproduction
• Prokaryotic cells

  • No nucleus
  • No membrane bound organelles
  • Mainly unicellular organisms
  • Generally less complex than eukaryote
  • Components float freely in cytoplasm
• Viruses

  • Non living
  • Cause variety of infectious diseases
  • Extremely small, only seen by electron microscope
  • Called “non cells” bc has no organelles, cytoplasm & chromosomes
• Virus (Structure)

  • Always contains genetic material
  • Usually a few enzymes
  • DNA held in capsids
  • Surrounded by matrix and then lipid envelope
  • Attachment proteins - attaches to host cell
• Binary fission

  The method of cell division used by prokaryotes involving replication of the circular DNA and plasmids followed by cytoplasmic division.