MICR-4010 Lecture Notes - Lecture 5: Hydrogenase, Lithotroph, Light-Independent Reactions
Document Summary
The further the rxns are apart on the reduction potential tower the greater amount of energy released. Electron donors are usually h2s, h+, s, n, fe. Assimilative reductions: when inorganic compounds are reduced for the purpose of using them for cell constituents. Energy is consumed and small amount of compounds are reduced. Chemoorganotrophs generate nadh during oxidation of organic molecules. Dissimilative reduction: large amount of electron acceptors are reduced and the product remains a small molecule which is excreted from cell. Chemolithotrophs: conserve energy from oxidation of inorganic electron donors. Facultative chemolithotrophs: more energy by organic molecule for oxidation. H2 oxidation = h2 + 1/2 o2 => h2o. Binds to h2 and reduces nad+ to nadh. Oxygenate h2 to make h20 to partake in oxygenic photosynthesis. H2s + 2 o2 => so4 + 2 h+ Common sulfur compounds used as electron donors = hydrogen sulfide (h2s), elemental sulfur (s), and thiosulfate (s2o3)