Electron Transport Chain ETC and Oxidative Phosphorylation Ox Phos

1
Electron Transport Chain (ETC)andOxidative
Phosphorylation (Ox Phos)
2
ETC and Ox Phos

• Electron Transport Chain (ETC) AKA respiratory
  chain
• importance allows conversion of reducing
  equivalents to ATP
• location inner mitochondrial membrane

3
Detailed Mitochondrial Structure
4
Sites are Used to Describe the ETC

• Molecules not completely known
• Sites I-IV
• Overview of the four

5
Many Well-known Poisons are Poisons of the ETC

• Analogy of waterline with valves at various spots

6
Site I in detail

• NADH
• FMN
• Fe-S
• CoQ10
• Know net reaction and name of enzyme

7
Sites II-IV

• Know net reactions and names of enzymes

8
Electron Flow per se Does not Cause ATP Synthesis
9
Q Cycle

• A proton gradient is developed

10
Mitchells Chemiosmotic Theory

• Proton gradient tightly coupled to ATP synthase

11
ATP Synthase is an Oligomeric Rotor

• Fo- oligomycin-sensitive integral membrane
  portion
• F1- hexamer of a- and ß-subunits
• g-subunit
• estimated to rotate at 7,000 rpm

12
Inhibitors of ATP Synthase

• Oligomycin
• others exist

13
Uncouplers of ATP Synthesis

• 2,4-DNP
• others exist
• one way of experimentally determining importance
  of proton gradient

14
PO Ratio

• Moles ATP
• Atoms oxygen
• Theoretically 3 (NAD) or 2 (FAD)
• Experimentally 2.8 is a ballpark real number

15
Regulation of ATP Synthesis

• Availability of ADP (usually)