Endosymbiosis Theory Essay

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What is the Endosymbiotic Hypothesis? It is a hypothesis that tells how mitochondria and chloroplasts evolved. It is sort of like two friends who moved in together and they live cohesively because they each do something to help out each other live. In other words the mitochondrion evolved from a small prokaryotic cell that was swallowed by a larger heterotrophic (not self-sustaining, dependent upon others for food) eukaryotic cell. The larger cell did not digest the smaller cell because the smaller cell could use photosynthesis to produce energy that the larger cell could not do. The eukaryotic cell provided protection and nutrients to the prokaryotic cell. Therefore the relationship became permanent. Mitochondria and chloroplasts have a double layered cell membrane wall. In the process of being swallowed the smaller cells would have been wrapped up in the cell membrane of the larger cell, giving it a double layered cell membrane. Both purple, aerobic bacteria (similar to mitochondria) and photosynthetic bacteria (similar to chloroplasts) only have one phospholipid bilayer, when they enter a cell through the process of endocytosis, which is a process of cellular ingestion by which the plasma membrane folds inward to bring substances into the cell they form a second layer, therefore forming a double phospholipid bilayer. Chloroplasts were formed when photosynthetic bacteria was swallowed up by the larger eukaryotic cell. They eventually lost their cellular wall and most of their DNA because they did not benefit the larger host cell. Much of the internal structure, and biochemistry of chloroplasts is very similar to cyanobacteria. Phylogenies built with bacteria, chloroplasts, and eukaryotic suggest that chloroplasts are closely related to cyanobacteria. Cyanobacteria is any group of photosynthetic autotrophic prokaryotic microorganisms possessing

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