Endosymbiotic Theory
1. Mitochondria formed through the endosymbiosis of a proteobacteria
2. Chloroplast formed from the endosymbiosis of a cyanobacteria
Primary Endosymbiosis
When a proteobacteria or a cyanobacteria is engulfed by a eukaryote
Second Endosymbiosis
Is when a eukaryote is engulfed by anther eukaryote
Evidence of Endosymbiosis
-Mitochondria and chloroplast have own DNA that is circular and led scientists to believe that they were separate organisms at one point.
-Sequence of that DNA is similar to bacteria
-They also have double membranes which shows evidence of being engulfed
-New mitochondria and plastids are formed only by a process similar to binary fission
-Internal structure and biochemistry of plastids is similar to cyanobacteria
What are some key evolutionary changes in the eukaryote cell that allowed for endosymbiosis?
1. Protective cell wall is lost
2.
Plasma membrane infold to increase SA 3. Cytoskeleton is formed 4. Internal membranes with ribosomes formed 5. DNA enclosed in a membrane 6. Microtubles form flagella enabling movement Cytokskeleton was added Internal membrane (allowed them to specialize) Lysosome
CFU
Colony forming units
