1 / 27

Electron Transport Chain

Electron Transport Chain. Electron Transport Chain. Mitochondrial Structure. Electron Transport Chain Overview. The ETC removes energy stored in the NADH and FADH 2 molecules to: create a proton gradient across the inner mitochondrial membrane convert O 2 to H 2 O.

erich-brady
Download Presentation

Electron Transport Chain

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electron Transport Chain

  2. Electron Transport Chain

  3. Mitochondrial Structure

  4. Electron Transport Chain Overview The ETC removes energy stored in the NADH and FADH2 molecules to: • create a proton gradient across the inner mitochondrial membrane • convert O2 to H2O. All reactions are redox reactions.

  5. Electron Transport Chain Animation ETC Animation

  6. ETC Components

  7. ETC Components: Complex I • 2 e- from NADH are transferred to Complex I • Protons are pumped across the inner mitochondrial membrane (IMM) by Complex I

  8. ETC Components: Q • e- are transferred from Complex I to ubiquinone (Q) • Q is a mobile component within the IMM

  9. ETC Components: Complex III • e- are transferred from Q to Complex III • Protons are pumped across the IMM by Complex III

  10. ETC Components: Cyt C • e- are transferred from Complex III to cytochrome c (cyt c) • cyt c is a mobile component on the surface of IMM, in the intermembrane space

  11. ETC Components: Complex IV • e- are transferred from cyt c to Complex IV • Protons are pumped across the IMM by Complex IV

  12. ETC Components: O2 • O2 is the final electron acceptor of the ETC • enough e- pass through the ETC to produce full H2O molecules

  13. FADH2 Pathway FADH2 FAD

  14. ETC Components: Complex II • 2e- are transferred from FADH2 to Complex II – can think of them passing directly to Ubiquinone • no protons are pumped across the IMM • e- are transferred from Complex II to Q and proceed through the rest of ETC FADH2 FAD

  15. ETC Thermodynamics Each electron transfer step is energetically favourable.

  16. Electrochemical Proton Gradient

  17. ETC Summary • NADH e- transferred to O2; three proton pumps activated • FADH2 e- transferred to O2; two proton pumps activated • electrochemical proton gradient formed across IMM

  18. Electron Transport Chain Animation ETC Animation

  19. Oxidative Phosphorylation

  20. Proton Motive Force: Chemiosmosis The electrochemical gradient (chemiosmosis) produced by the ETC can now be used to generate ATP through the process of oxidative phosphorylation (OXPHOS). OXPHOS occurs through the enzyme complex ATP synthase. OXPHOS Animation

  21. ATP Synthase Complex Two components: • F0 – proton channel / rotor embedded in IMM • F1 – catalytic sites that phosphorylate ADP to ATP ATP synthase rotation

  22. ATP Production oxidative phosphorylation - ATP is produced as protons flow through ATP synthase. In general: • 1 NADH  2.5 – 3 ATP molecules • 1 FADH2  1.5 – 2 ATP molecules The ETC is coupled with ATP synthesis. The latter is dependent on the former.

  23. ATP Production

  24. Glycolysis NADH NADH produced in glycolysis must be transported from the cytoplasm into the mitochondria to enter the ETC. Two shuttle mechanisms: • glycerol phosphate shuttle • malate-aspartate shuttle

  25. Glycerol Phosphate Shuttle

  26. Malate-Aspartate Shuttle

  27. ATP Production Summary

More Related