CONCEPT 3. Prokaryotes

• What do all prokaryotes contain?

  • Cell membrane
  • DNA located in the nucleoid
  • Cytoplasm
  • Ribosomes
• Why are cyanobacteria significant to the evolution of life?

  Major contributors to the oxygenation of the Earth and were the first organisms to undergo photosynthesis.
• What are the two prokaryotic domains?

  Bacteria, Archaea
• What are resting spores/endospores?

  A feature of bacteria that is there is a lack of nutrients, bacteria is able to simplify itself into a dormant state and revive itself later and function as normal.
• How are prokaryotes used by humans?

  • Recycling of resources such as water
  • GMO pharmaceuticals
  • GMO plants
• Features of gram-positive bacteria.

  • Stain: PURPLE
  • Cell wall: simple, single and thick layer
  • Peptidoglycan layer: thicker and multilayered
  • Outer membrane: not present
  • Lipid content: low levels
  • Antibiotic response: susceptible
  • Toxicity: less toxic
• Features of gram-negative bacteria

  • NO STAIN
  • Cell wall: structurally complex, double layered and thin
  • Peptidoglycan layer: thin and single
  • Outer layer: present
  • Lipid content: 20-30%
  • Antibiotic response: resistant
  • Toxicity: More toxic
• Structure of a prokaryote.

  A) pilis

  B) cell membrane

  C) capsule

  D) cytosol

  E) flagellum

  F) nucleoid

  G) ribosome

  H) cell wall