Terms applied to cells - ocean. Evidence of the antiquity...

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Terms applied to cells Heterotroph (other-feeder): an organism that obtains its energy from another organism. Animals, fungi, bacteria, and mant protistans are heterotrophs. Autotroph (self-feeder): an organism that makes its own food, it converts energy from an inorganic source in one of two ways. Photosynthesis is the conversion of sunlight energy into C-C covalent bonds of a carbohydrate , the process by which the vast majority of autotrophs obtain their energy. Chemosynthesis is the capture of energy released by certain inorganic chemical reactions. This is common in certain groups of likely that chemosynthesis predates photosynthesis. At mid-ocean ridges, scientists have discovered black smokers, vents that release chemicals into the water. These chemical reactions could have powered early ecosystems prior to the development of an ozone layer that would have permitted life to occupy the shallower parts of the
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Unformatted text preview: ocean. Evidence of the antiquity of photosynthesis includes: a) biochemical precursors to photosynthesis chemicals have been synthesized in experiments; and b) when placed in light, these chemicals undergo chemical reactions similar to some that occur in primitive photosynthetic bacteria. Prokaryotes are among the most primitive forms of life on Earth. Remember that primitive does not necessarily equate to outdated and unworkable in an evolutionary sense, since primitive bacteria seem little changed, and thus may be viewed as well adapted, for over 3.5 Ga. Prokaryote (pro=before, karyo=nucleus): these organisms lack membrane-bound organelles , as seen in Figures 5 and 6. Some internal membrane organization is observable in a few prokaryotic autotrophs, such as the photosynthetic membranes associated with the photosynthetic chemicals in the photosynthetic bacterium Prochloron ....
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This note was uploaded on 11/22/2011 for the course CHEMISTRY CHM1025 taught by Professor Laurachoudry during the Fall '10 term at Broward College.

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