3Three Prokaryotic Cells Typical Bacterial CellMurein WallNaked Circular DNA genome70S RibosomesCarries out Aerobic RespirationEnzymatic Glycolysis and Krebs Cycle in CytosolElectronic ETS and Ox Phos in/across MesosomesHighly efficient ATP production from simple fuel molecules36 ATP per glucosenucleoid70S ribosomesKrebs CycleETS + Ox PhosCell MembraneMurein Wall
4Light Reactions + Photo Phos Three Prokaryotic CellsTypical Cyanobacterial CellMurein WallNaked Circular DNA genome70S RibosomesCarries out PhotosynthesisEnzymatic Calvin Cycle and Condensation Reactions in CytosolElectronic Light Reactions and Photo Phos in/across Thylakoid MembranesHighly efficient ATP productionHighly efficient synthesis of a wide range of organic molecules from CO2nucleoid70S ribosomesCalvin CycleLight Reactions + Photo PhosCell MembraneMurein Wall
5Three Prokaryotic Cells Archaeon CellNo Wall (Contractile Vacuole avoids burst)Multiple protein-bound DNA molecules in genome70S becoming 80S RibosomesMetabolism by Fermentation OnlyEnzymatic Glycolysis and Fermentation Reactions in CytosolComparatively inefficient ATP production2 ATP per glucoseMust consume huge amounts of fuelHighly evolved endocytosis (phagocytosis)--leading to endosymbiosisLarge cytoplasm requires highly developed endomembrane system from mesosomesFormation of nuclear envelope to avoid digesting its own DNATransposon system for acquiring/incorporating more DNA into genomenucleoid80S ribosomesGlycolysis + FermentationEndomembrane SystemCell MembraneNone (Contractile Vacuole)
6Binary Fission of Organelle Three Prokaryotic CellsWall LossCritical Gene MovementEndocytosisBinary Fission of OrganelleMany critical genes moved into the host nucleoid/nucleusThe endosymbiont has become an organelle...no longer capable of independent respirationThe mitochondrion has two bounding membranesThe host vesicle membraneThe endosymbiont cell membrane
7Binary Fission of Organelle Three Prokaryotic CellsWall LossCritical Gene MovementEndocytosisBinary Fission of OrganelleA critical gene moved into the host nucleoid/nucleus is the rubisco small subunitThe endosymbiont has become an organelle...no longer capable of independent photosynthesisThe chloroplast has two bounding membraneshost vesicle membrane and endosymbiont cell membrane
8Three Prokaryotic Cells The fermentation-only archaeon has taken in a bacterial cell and a cyanobacterial cell as endosymbiontsBy not digesting them completely, but removing the cell wall, the archaeon has gained two gigantic biochemical pathways: respiration and photosynthesisBy moving critical genes from each endosymbiont, using its transposon feature, the archaeon has trapped both endosymbionts as permanent organellesThis is almost a eukaryotic plant cell!
9Three Prokaryotic Cells The archaeon still needs to convert its endomembrane system into endoplasmic reticulumAnd consolidate the encircling membranes into a nuclear envelopeAnd make its circular chromosomes linear with telomeresAnd finish the evolution of the 80S ribosomesIt also needs to entrap some spirochetes for a cytoskeleton and for a eukaryotic flagellumThe sequence of these steps relative to the endosymbiont capture is still being resolved!