BIOC 300B Lecture Notes - Lecture 27: Cytochrome C, Alpha Helix, Oxidoreductase
5 Apr 2018
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The etc: 4 membrane-associated complexes end up producing two reduced cytochrome. Large membrane protein with alpha helices that span the membrane. Has 2 heme groups and 3 copper ions. Mechanism: 2 x cytochrome c delivers its electrons to the copper centre (cub) and then to a heme group (heme a3) following electron drop-off, fe3+ and cu2+ are oxidized to fe2+ and cu+ 2: oxygen enters and forms a peroxide bridge. 4 total electrons are shuttled two protons are taken up from the matrix and two molecules of water are released. > the stoichiometry of cytochrome c oxidase mechanism the dg " = -55. 4 kcal/mol = highly favourable. The 4 p+ pulled out of the matrix contributes 20. 8 kcal/mol to the dg of the proton gradient and the rest of the energy pumps out another 4 protons: A total of 8 p+ moved from matrix and 4 enter the cytosol.
