WEEK 5 - ENDOSYMBIOTIC THEORY

ENDOSYSMBIOTIC THEORY

Suggest that :

• Eukaryotes arose from a symbiotic relationship between various prokaryotes
• Heterotropic (aerobic) bacteria became mitochondria
• Cyanobacteria (photosynthetic) became chloroplast
• Hoat cell was a large eukaryotic cell

The origin of eukaryote cell

Evidence of endosymbiosis:

1. mitochondria and chloroplasts are similar in size and marphology to bacterial prokaryotic cells
2. mitochondria and chloroplasts divide by binary fission, just as bacteria do, and not mitosis as eukaryotes do
3. chemical distint membrane systems
4. mitochondria and chloroplasts have their own DNA and their own ribosomes
5. mitochondria arise from pre-existing mitochondria; chloroplast arise from pre-existing chloroplasts 
6. organelle ribosomes are more similar in size to prokaryotic which have 30s and 50s 
7. many antibiotics that kill or inhibit bacteria also inhibit protein synthesis of these organelles
8. phylogenetic studies using comparative ribosomal RNA sequencing demonstrates that both mitochondria and plastids are related to Bacteria    

In class we learned to differentiate the mitochondria and chloroplast using the venn diagram.