Photosynthesis and Cellular Respiration Essay Example | Topics and Well Written Essays - 1250 words

Photosynthesis and Cellular Respiration - Essay poserPhylogenetic analysis of Mg-tetrapyrrole biosynthesis genes reveals that anoxygenic photosynthetic processes became evident in primitive organisms like certain bacteria before the oxygenic variety in other organisms like cyanobacteria (Xiong and Bauer, 2002). Joint analyses of the pigment genes and reaction centers open yielded stronger evidence to this effect (Xiong and Bauer, 2002). At the time when photosynthesis became a rudimentary process for goose egg storage in arcane organisms cellular internal ventilation system was still to evolve and the dexterity release mechanism for utilizing the photosynthetic stored energy used processes that sourced their electrons from suppliers other water (Todar, Undated). Later, genetic guide mechanisms between endosymbiotic bacteria, their closest living relatives being the proteobacteria, and their pre-eukaryotic cellular hosts inducted cell cell organelles like mitochondria and chlor oplasts (Simpson et al, 2002) into the pre-eukaryotic system and cellular respiration became possible. Some time during the endosymbiotic processes there was gene transfer from the bacteria to the pre-eukarytic cells whereby the bacterial genome was reduced and much of the remaining genetic materials got encoded in the cellular nucleus while, locally, nearly of the bacterial genetic materials were encoded within the organelle, mitochondrion or otherwise, to form localized DNA entirely associated with organelle function (Chihade et al, 2000). While the induction of the mitochondria into the pre-eukaryotic cells to produce the eukaryotic system shall be dealt with later in the study a short comparison by organisms will now be made of photosynthesis and cellular respiration processes. ComparisonThe following table will be used to compare and contrast photosynthesis and cellular respiration in the species of euglenoids that have primitive plastids (Borza et al, 2005). Euglenoids are e ither autotrophs, photosynthetic with chlorophyll a and b chloroplasts, or heterotrophs with parasitic or absorptive nutrition. Some of them also have motile mechanisms like flagella or cilia. It is luminary that euglenoids with plastids acquired them through secondary endosymbiosis and, thus, the plastids are not as developed as those of more evolutionary right species (Borza et al, 2005). It is also notable that euglenoids with plastids also use absorptive nutrition, absorbing organic matter from their environs, as appurtenant dietary processes. Though they may be photosynthetic they can respire both aerobically and anaerobically (Hoffmeister et al, 2004). Anaerobically, these organisms store energy in the form of fatty acids (waxes) that are broken down when oxygen becomes available more plenteously (Hoffmeister et al, 2004). This makes these organisms so interesting. It is notable that both photosynthesis and cellular respiration in euglenoids with chloroplasts are still not to the full understood (Hoffmeister et al, 2004 Lonergan and Sargent, 1979). Nevertheless, these processes have been simplistically compared and contrasted in the following table.PhotosynthesisCellular RespirationOrganismEuglena gracilisEuglena gracilisEnergy Source sunninessChemical energy in sugars (anaerobic) and sugars/fatty acids