EPS SCI 3 Lecture Notes - Lecture 7: Anoxygenic Photosynthesis, Isotope Fractionation, Methanogenesis
30 Oct 2017
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Document Summary
Allow organism to grow and reproduce, maintain their structures, and respond to their environments. Elements have different isotopes with different number of neutrons. Most abundant form of carbon: carbon-12 (stable) Because thei enzymes react with them faster, resulting in a significant isotopic fractionation between the original substrate (original isotopic composition), the biological product (isotopically lighter) and the residual substrate (isotopically heavier) When microbes eat that food, they eat the lighter 12c. Examples of stable isotopes used in geochemistry detect biological activity. Carbon analysis of methane-bearing fluid inclusions in 3. 5 gyr old hydrothermal. Methanogenesis was responsible for creating this isotopic signature precipitates from pilbara craton, australia. Yes, methanogenesis was one of the first processes! Microbial methanogenesis could have started at hydrothermal systems. Hydrothermal circulation vapor exits vent returns to seafloor. They wanna find out if methane came from biological processes. We see a separation of sulfide and sulfate minerals. Also, it must be a chemoautotrophic process.
