26. Electron Carriers NAD + or FAD There are 2 sites of entry for electrons into the electron transport chain: Both are coenzymes for dehydrogenase enzymes The transfer of electrons is not directly to oxygen but through coenzymes
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34. Reduction Potentials Number of electrons transferred in the redox reaction Faraday’s constant (96485 J/volt/mole) Crucial equation: G o ' = -n F E o ' The relative tendency to accept e - s and become reduced. = E o '(acceptor) - E o '(donor) E 0 ’=standard reduction potential. If E o ' is positive, an electron transfer reaction is spontaneous ( G o ' <0)
44. CYTOPLASM OUTER MEMBRANE MATRIX INNER MEMBRANE Figure 3. The malate-aspartate shuttle. OAA Malate (1) e - NAD + e - Glu 0 (6) Glu 0 Asp -1 (4) KG KG Malate (2) e - e - OAA NADH NAD + (3) e - Complex I e - NAD + Glucose Pyruvate GLYCOLYSIS NADH Asp -1 (5)
45. CYTOPLASM INNER MEMBRANE MATRIX FAD Glycerol-3-phosphate dehydrogenase (2) DHAP OUTER MEMBRANE Figure 4. Glycerol phosphate shuttle. Cytoplasmic glycerol 3-phosphate dehydrogenase (1) oxidizes NADH. Glycerol 3-phosphate dehydrogenase in the inner membrane (2) reduces FAD to FADH 2 . G3P Dihydroxyacetone phosphate (DHAP) NAD + 3-phosphate Glycerol e (1) FADH 2 e CoQ e O 2 e NADH Glucose Pyruvate GLYCOLYSIS NAD +