BIOL 3P30 Lecture Notes - Lecture 12: Nadph Oxidase, Semiquinone, Myoglobin
22 Aug 2015
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Lecture 5 - oxygen cascade, electron leak, ros, and antioxidant enzymes po2 drops continually from atmosphere to cells: Virtuall all tissues operate in a similarly po2 environment. Measuring intracellular po2 signal, fluorescent signals myoglobin po2 inside mitochondria is very low. Oxygen bars with 100% oxygen will have some effect on change in metabolic process that could be detrimental. Cytochrome c oxidase (complex iv) has a very high affinity for oxygen. Km (oxygeb) <0. 1 m = 0. 2mmhg; this is where cytochrome c oxidase works at half its rate. In this case oxygen concentration is being altered; everything else is staying the same. Vmax occurs around 2-5 mmhg and this is where it cytochrome c is working at its max. Cytochrome oxidase fully o2 saturated at normal physiological intracellular po2. Therefore increasing po2 will not increase reaction rate under basal conditions. Gets the extra electrons from these respiration reactions. Sites of ros production in the electron transport chain.
