Endosymbiotic Theory Essay

The endosymbiotic theory explains the evolution of the eukaryotic stall and eukaryotic organelles by phagonecytocis of small procaryotic stalls. This theory states that some of the organelles in directlys eukaryotic cells were once procaryotic bacteria.In this theory, the prototypical eukaryotic cell was probably an amoeba- exchangeable nucleated (probably desoxyribonucleic acid in a nucleoid region not an unquestionable nucleus) procaryotic cell that got nutrients by phagocytosis (engulfing nutrients or other cells) Some of these unicellular amoeba-like organisms engulfed prokaryotic cells that somehow were not digested within the organism. In the process of being engulfed the smaller cells would stand been wrapped in membrane from the bigger cell, at once we expect double membranes in mitochondria and chloroplasts. The symbiotic relationship was beneficial because the legions cell would have provided essential nutrients to the engulfed prokaryotic cell in exchange th e smaller prokaryotic cell used these nutrients to combine ATP molecules, this ATP was used as an muscularity source by the legion cell. The smaller prokaryotic cell was granted a safe environment as well as receiving nutrients from the larger innkeeper cell.The small prokaryotic cell developed a symbiotic (mutually beneficial) relationship with the military cell. This smaller prokaryotic cell would ultimately become mitochondria or chloroplasts. Mitochondria would have been create when bacteria capable of aerobic ventilation system were ingested by a such(prenominal) larger cell. Chloroplasts formed when photosynthetic bacteria were ingested. They in conclusion lost their cell wall and much of their DNA because they were not of benefit within the military cell. Mitochondria and chloroplasts cannot grow outside their host cell in normal conditions because they right off depend on the cell for rampart and nutrients. The reason we do not see this type of symbiotic relat ionship today is because conditions be much variant this instant then they were on earth millions of years ago when this symbiotic event first took place.Scientists can support the endosymbiotic hypothesis because the characteristics of efficacy organelles are so similar to those of prokaryotes. talent organelles have their own set of inheritable information it is not found  enfold in a nucleus only a circular ring in a nucleoid region just like prokaryotic DNA. Mitochondria and chloroplasts have their own ribosomes this would indicate that at one time energy organelles were able be self sufficient. two organelles have a double membrane, a remnant of ancient endosymbiotic event.Also when a cell divides by mitosis the energy organelles twin the same way as do prokaryotic bacteria, by binary fission. Mitochondria and chloroplasts are about the same size as prokaryotic cells. The DNA of these energy organelles is different from the DNA found in the cells nucleus. at tha t place is some evidence of bacterial DNA in these energy organelles that suggests that long ago they were once prokaryotic cells.Biology, Neil A. Campbell & Jane B. ReeceBenjamin e. e. cummings 7th Edition, 2006Investigating Biology, Neil A Campbell & Jane B.ReeceBenjamin e. e. cummings 6th Edition 2007