Endosymbiotic Theory

The endosymbiotic theory explains the evolution of the eukaryotic carrellphone and eukaryotic organelles by ph agocytocis of small procaryotic jail cells. This theory states that some of the organelles in todays eukaryotic cells were once prokaryotic bacterium. In this theory, the first eukaryotic cell was probably an amoeba-like nucleated (probably DNA in a nucleoid piece non an actual nucleus) prokaryotic cell that got nutrients by phagocytosis (engulfing nutrients or other cells) Some of these unicellular amoeba-like organisms engulfed prokaryotic cells that somehow were non digested inwardly the organism. In the process of being engulfed the smaller cells would devote been engrossed in membrane from the larger cell, today we substantiate twice membranes in mitochondria and chloroplasts. The symbiotic relationship was beneficial because the forces cell would kick in provided essential nutrients to the engulfed prokaryotic cell in exchange the smaller prokaryotic c ell used these nutrients to synthesize adenosine triphosphate molecules, this ATP was used as an energy root system by the forces cell. The smaller prokaryotic cell was stipulation a estimable environment as well as receiving nutrients from the larger military cell. The small prokaryotic cell certain a symbiotic (mutually beneficial) relationship with the host cell. This smaller prokaryotic cell would in the end become mitochondria or chloroplasts. Mitochondria would have been form when bacteria capable of aerobic respiration were ingested by a much(prenominal) larger cell. Chloroplasts formed when photosynthetic bacteria were ingested. They eventually illogical their cell wall and much of their DNA because they were non of value within the host cell. Mitochondria and chloroplasts cannot grow outside their host cell in normal conditions because they now depend on the cell for protection and nutrients. The reason we do not foregather this cause of symbiotic relationshi p today is because conditions are much anti! thetical now then they were on earth millions of long sequence ago when this symbiotic event first took place. Scientists can manage for the endosymbiotic hypothesis because the characteristics of energy organelles are so similar to those of prokaryotes.

power organelles have their own set of genetic information it is not found enclosed in a nucleus merely when a circular ring in a nucleoid verdant just like prokaryotic DNA. Mitochondria and chloroplasts have their own ribosomes this would cite that at one time energy organelles were able be self sufficient. Both organelles have a double membrane, a remnan t of ancient endosymbiotic event. Also when a cell divides by mitosis the energy organelles replicate the corresponding way as do prokaryotic bacteria, by binary fission. Mitochondria and chloroplasts are about the kindred size as prokaryotic cells. The DNA of these energy organelles is diametrical from the DNA found in the cells nucleus. There is some tell 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 cummings; 6th Edition 2007 If you want to get a panoptic of the mark essay, order it on our website: OrderCustomPaper.com

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