Oxidative Phosphorylation

• What is the last stage of aerobic respiration?

  Oxidative phosphorylation
• Where does oxidative phosphorylation take place?

  At the inner mitochondrial membrane
• What are the main products of oxidative phosphorylation?

  Many molecules of ATP and water from oxygen
• What is the current model for oxidative phosphorylation?

  The chemiosmotic theory
• What does the chemiosmotic theory state?

  Energy from electrons is used to pump protons up their concentration gradient
• What is the role of the electron transport chain in oxidative phosphorylation?

  It passes electrons through a chain of proteins to pump protons
• How do protons flow back into the matrix during oxidative phosphorylation?

  By facilitated diffusion through ATP synthase
• What acts as the 'final electron acceptor' in oxidative phosphorylation?

  Oxygen
• What is the result of protons flowing down their concentration gradient?

  It provides energy for ATP synthesis
• What does oxygen combine with at the end of the electron transport chain?

  Protons and electrons to form water
• What is the outline of oxidative phosphorylation?

  • Hydrogen atoms are donated by reduced NAD (NADH) and reduced FAD (FADH2)
  • Hydrogen atoms split into protons (H+ ions) and electrons
  • High energy electrons enter the electron transport chain
  • Released energy transports protons across the inner mitochondrial membrane
  • A concentration gradient of protons is established
  • Protons return to the matrix via ATP synthase
  • Movement of protons provides energy for ATP synthesis
  • Oxygen combines with protons and electrons to form water
• What is the structure and function of the electron transport chain?

  • Made up of a series of membrane proteins/electron carriers
  • Positioned close together for efficient electron transfer
  • Inner membrane is impermeable to hydrogen ions
  • Electron carriers pump protons across the membrane to establish a concentration gradient