Complex III of Electron Transport Chain: Difference between revisions
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The UQ<sup><big> • -</big></sup>, the <scene name='Complex_III_of_Electron_Transport_Chain/Focus_semiuq/1'>conjugate base</scene> of the semiquinone, which was formed at Qp as described above and is shown here as <font color=red>stigmatellin</font> is oxidized to the full UQ when it <scene name='Complex_III_of_Electron_Transport_Chain/Electron_semi_to_hem_l/2'>passes an electron</scene> to heme b<sub>L</sub>. The <scene name='Complex_III_of_Electron_Transport_Chain/Electron_hem_l_to_hem_h/1'>electron</scene> is then passed from the Fe of heme b<sub>L</sub> to the Fe of Heme b<sub>H</sub>, and with Heme b<sub>H</sub> being next to UQ bound at the Q<sub>n</sub> site (Binding site is located on the <scene name='Complex_III_of_Electron_Transport_Chain/Hem_h_next_to_surface/3'> surface</scene> with a black arrow.), the <scene name='Complex_III_of_Electron_Transport_Chain/Electron_hem_h_to_uq/3'>electron</scene> is passed to UQ. With only one electron being passed in this series of reaction the UQ is reduced to UQ<sup><big> • -</big></sup>, and becomes UQH<big><sup> •</sup></big> when it accepts a <scene name='Complex_III_of_Electron_Transport_Chain/Proton_matrix_in/1'>proton</scene> which comes from the matrix. The end products of the first half of the Q cycle are an ubiquinol oxidized to ubiquinone at the Q<sub>p</sub> site, a reduced cyt c and an ubiquinone reduced to semi-ubiquinone at the Q<sub>n</sub> site. | The UQ<sup><big> • -</big></sup>, the <scene name='Complex_III_of_Electron_Transport_Chain/Focus_semiuq/1'>conjugate base</scene> of the semiquinone, which was formed at Qp as described above and is shown here as <font color=red>stigmatellin</font> is oxidized to the full UQ when it <scene name='Complex_III_of_Electron_Transport_Chain/Electron_semi_to_hem_l/2'>passes an electron</scene> to heme b<sub>L</sub>. The <scene name='Complex_III_of_Electron_Transport_Chain/Electron_hem_l_to_hem_h/1'>electron</scene> is then passed from the Fe of heme b<sub>L</sub> to the Fe of Heme b<sub>H</sub>, and with Heme b<sub>H</sub> being next to UQ bound at the Q<sub>n</sub> site (Binding site is located on the <scene name='Complex_III_of_Electron_Transport_Chain/Hem_h_next_to_surface/3'> surface</scene> with a black arrow.), the <scene name='Complex_III_of_Electron_Transport_Chain/Electron_hem_h_to_uq/3'>electron</scene> is passed to UQ. With only one electron being passed in this series of reaction the UQ is reduced to UQ<sup><big> • -</big></sup>, and becomes UQH<big><sup> •</sup></big> when it accepts a <scene name='Complex_III_of_Electron_Transport_Chain/Proton_matrix_in/1'>proton</scene> which comes from the matrix. The end products of the first half of the Q cycle are an ubiquinol oxidized to ubiquinone at the Q<sub>p</sub> site, a reduced cyt c and an ubiquinone reduced to semi-ubiquinone at the Q<sub>n</sub> site. | ||
The second half of the Q cycle is different form the first half in that at the Q<sub>n</sub> site | The second half of the Q cycle starts the same as the first half with the binding of UQH<sub>2</sub> at the Q<sub>p</sub>, proceeds from there the same as in the first half and only is different form the first half in that at the end of the cycle at the Q<sub>n</sub> site a semi-ubiquinone is reduced to ubiquinol so that during a complete cycle at the Q<sub>n</sub> site an ubiquinone is reduced to ubiquinol. | ||
SUMMARY:<br> | SUMMARY:<br> | ||
