Oxidative phosphorylation

• What is the aim of oxidative phosphorylation?

  To describe the electron transport chain (ETC) and explain the importance of mitochondrial membranes in ATP generation.
• What is the role of the electron transport chain in generating ATP?

  The ETC transfers electrons from reduced NAD and FAD to produce ATP through oxidative phosphorylation.
• Why is oxygen important in the electron transport chain?

  Oxygen acts as the terminal electron acceptor, forming water when it combines with electrons and protons.
• How is ATP synthesized by chemiosmosis?

  ATP is synthesized by the movement of protons down their concentration gradient through ATP synthase.
• What is the significance of mitochondrial membranes in oxidative phosphorylation?

  The membranes create a proton gradient essential for ATP synthesis during chemiosmosis.
• What is oxidative phosphorylation?

  It is the final stage of aerobic respiration involving reduced NAD, reduced FAD, and the electron transport chain.
• What are cytochromes?

  Cytochromes are proteins that are part of the electron transport chain.
• What is cytochrome oxidase?

  Cytochrome oxidase is an enzyme that receives electrons from cytochromes in the electron transport chain.
• What is reduction?

  Reduction is the gain of electrons, gain of hydrogen, or loss of oxygen.
• What is oxidation?

  Oxidation is the loss of electrons, loss of hydrogen, or gain of oxygen.
• What are the products of glycolysis for each molecule of glucose?

  • 2 ATP
  • 2 NADH
  • 2 pyruvate
• What are the products of the link reaction for each molecule of glucose?

  • 2 NADH
  • 2 CO2
  • 2 acetyl-CoA
• What are the products of the Krebs cycle for each molecule of glucose?

  • 4 CO2 (produced by decarboxylation)
  • 2 ATP (produced by substrate-level phosphorylation)
  • 6 NADH (produced by redox reactions)
  • 2 FADH2 (produced by redox reactions)
• How is the potential energy in NADH and FADH2 transferred to ATP?

  The potential energy is transferred to ATP through oxidative phosphorylation in the electron transport chain.
• How much ATP can NADH yield?

  NADH can yield 2.5 ATP.
• How much ATP can FADH2 yield?

  FADH2 can yield 1.5 ATP.
• What is the total ATP produced from one molecule of glucose?

  The total ATP produced is 32 ATP.
• Why is the theoretical yield of 32 ATP rarely achieved?

  Because some protons leak across the mitochondrial membrane and some ATP is used for active transport.
• What happens if oxygen is not present in respiration?

  Protons and electrons would back up along the chain, halting the process.
• What is the effect of cyanide on respiration?

  Cyanide inhibits the final enzyme in the electron transport chain, preventing water formation.
• Describe the part played by the inner membrane of a mitochondrion in producing ATP.

  • Contains the electron transport chain.
  • Creates a proton gradient for ATP synthesis.
  • Houses ATP synthase for ATP production.

  
• What is the final acceptor of electrons in the electron transport chain?

  Oxygen is the final acceptor of electrons.
• What product is formed when electrons combine with oxygen at the end of the electron transport chain?

  Water is formed when electrons combine with oxygen.
• What is the energy lost by electrons used for in the electron transport chain?

  The energy lost by electrons is used to drive the production of ATP.
• How does the electron transport chain contribute to ATP synthesis?

  The electron transport chain liberates energy used to synthesize ATP by oxidative phosphorylation.
• What is the role of hydrogen atoms in the electron transport chain?

  Hydrogen atoms combine with NAD and FAD, donating electrons to the first molecule in the ETC.
• What happens to protons released from hydrogen atoms during the electron transport chain process?

  Protons are actively transported across the inner mitochondrial membrane into the intermembrane space.
• What is the significance of the proton gradient created by the electron transport chain?

  The proton gradient is essential for ATP synthesis through chemiosmosis.
• How does the accumulation of protons in the intermembrane space affect ATP production?

  The accumulation of protons creates a concentration gradient that drives ATP synthesis when protons flow back into the matrix.
• What is the overall process of oxidative phosphorylation?


  transfer of electrons through the ETC, creating a proton gradient that drives ATP synthesis.