Oxidative Phosphorylation

complex 1
1. largest
2. NADH --> NAD+H+2e-
3. 2e- + 2H+ + ubiquinon (Q) --> ubiquinol (QH2)
  1. hydrophobic molecule - not a protein
4. electrons pass through iron-sulpher proteins
  1. allows H+ to be pumped across
complex 2
1. succinate + Q --> fumerate + QH2
complex 3
1. step 1
  1. QH2 oxidised release 2e-
    1. cytochrome accept 1 e-
      1. 2H+ pumped across
        remaining e- rebinds to Q forming Q-
2. step 2
  1. Second QH2
    1. extra e- binds to Q- with 2H+
      1. reforming QH2
        shuttling
complex 4
1. cytochrome C loses 4e-
  1. pump 4H+
  2. reduce O2 to H2O
ATP synthase
1. H+ ions move down electrochemical gradient through complex
  1. Y unit (central axis)
    1. rotates
      1. B subunit cycles between states
        open/empty - ADP and Pi bind- lose
        tight - bind to produce ATP
        cycles back to release 34 ATP
end products ATP
1. inhibit
  1. at rest
    1. increase proton motive force and low flow of protons/e- transfer
start products ADP
1. activate
  1. during exercise
    1. increase proton movement, decrease in proton motive force
inhibition
1. inhibit electron chain in complex 4
  1. bind to O2
    1. carbon monoxide, cyanide
2. inhibit ATP synthase
  1. block h+ flow
  2. uncoupling agents
    1. prevent proton gradient
    2. generate heat
      1. protons flow but don't produce ATP

Resource summary

	Created by devans1 over 10 years ago