Oxidative Phosphorylation

Definition

Oxidative phosphorylation is a metabolic process that takes place in the mitochondria, where ATP is produced as electrons are transferred through a series of proteins in the electron transport chain, ultimately combining with oxygen to form water. This process is crucial for energy production in cells and connects various aspects of metabolism, cellular respiration, and bioenergetics.

5 Must Know Facts For Your Next Test

1. Oxidative phosphorylation accounts for approximately 90% of the ATP generated during cellular respiration.
2. The process occurs in the inner mitochondrial membrane, where the electron transport chain is embedded.
3. Oxygen serves as the final electron acceptor, enabling the transfer of electrons and preventing the backup of electrons in the chain.
4. Proton pumping into the intermembrane space creates a proton gradient that drives ATP synthesis via chemiosmosis.
5. Disruptions in oxidative phosphorylation can lead to decreased ATP production and contribute to various diseases, including mitochondrial disorders.

Review Questions

• How does oxidative phosphorylation relate to the production of ATP during cellular respiration?
  • Oxidative phosphorylation is essential for ATP production in cellular respiration as it occurs after glycolysis and the citric acid cycle. The high-energy electrons from NADH and FADH2 are transferred through the electron transport chain, which creates a proton gradient. This gradient drives ATP synthase to convert ADP and inorganic phosphate into ATP, significantly increasing the energy yield compared to anaerobic processes.
• Evaluate the role of oxygen in oxidative phosphorylation and its importance for aerobic organisms.
  • Oxygen acts as the final electron acceptor in oxidative phosphorylation, allowing electrons to flow through the electron transport chain without interruption. This is crucial for aerobic organisms because, without oxygen, electron transport would cease, halting ATP production. The ability to use oxygen for efficient energy extraction allows aerobic organisms to sustain higher metabolic rates compared to anaerobic organisms, highlighting oxygen's vital role in energy metabolism.
• Analyze how disruptions in oxidative phosphorylation can impact overall cellular metabolism and contribute to disease.
  • Disruptions in oxidative phosphorylation can lead to decreased ATP production, causing energy deficits in cells that rely heavily on aerobic metabolism. This reduction in energy can impair cellular functions and lead to metabolic disorders. Mitochondrial diseases exemplify this issue, where mutations affecting components of the electron transport chain result in symptoms ranging from muscle weakness to neurodegeneration, emphasizing how vital efficient oxidative phosphorylation is for maintaining health.

Related terms

Electron Transport Chain: A series of protein complexes located in the inner mitochondrial membrane that facilitate the transfer of electrons derived from NADH and FADH2, ultimately leading to ATP synthesis.

Chemiosmosis: The movement of ions across a selectively permeable membrane, generating a proton gradient that powers ATP synthesis during oxidative phosphorylation.

ATP Synthase: An enzyme that uses the proton gradient created by the electron transport chain to convert ADP and inorganic phosphate into ATP during oxidative phosphorylation.