GMan Chapter 8 - Organelles

  1. Average number of mitochondria per cel
    • 100-1000
    • Depends on the cell's energy demand
  2. Organisms with chloroplasts
    • Plants
    • Algae
  3. Chloroplast structures
    • Stroma - Photosynthetic fluid
    • Thylakoid - Sacks filled with stroma
    • Grunam - Stacks of thylakoids
  4. What are plastids?
    • Plant organelles:
    • Chloroplasts
    • Amyloplasts - Starch storage
    • Chromplasts - Pigment storage
  5. Basis of the endosymbiont theory
    Gene expression in mitochondria and chloroplasts resembles prokaryrote processes
  6. Ancestral prokaryotic cell
    The cell that first engulfed mitochondria (and chloroplasts)
  7. Evidence of endosymbiosis
    • Organelles have their own DNA
    • Organlles have prokaryote-like ribosomes
    • Organelles have double membranes
    • Organelle membrane proteins are prokaryote-like
  8. Why was forming a symbiotic relationship with mitochondria favourable?
    Increasing oxygen concentrations, meant the previously anaerobicĀ host cell could survive and thrive as oxygen increased
  9. Why is oxygen-based metabolism preferred?
    It releases considerably more energy per unit of food
  10. What kind of cell engulfed the first mitochondrion?
    Early anaerobicĀ eukaryote (the DNA would be enclosed)
  11. Cyanophora paradoxa
    • Transition between endosymbiont and plastic (cyanelles)
    • Cyanalles contain peptidoglycan layer and photosynthetic pigments in thylakoid membrane
  12. What remains in the modern mtGenome?
    • Code for:
    • 13 Cellular respiration proteins
    • 22 tRNAs (different code)
    • 2 rRNAs
  13. Promiscuous DNA
    DNA that is transferred (uploaded) from one organelle to another
  14. Structor of organelle genomes
    Majority have single circular DNA
  15. Dinoflagellate genome
    Many, small, circular molecules
  16. Paramesium and Chlamydomonas genomes
Card Set
GMan Chapter 8 - Organelles