Oxidative phosphorylation

Definition

Oxidative phosphorylation is a metabolic process that produces ATP through the transfer of electrons from NADH and FADH2 to oxygen via the electron transport chain, coupled with the phosphorylation of ADP to ATP. This process is vital for cellular energy production, linking it to other metabolic pathways such as the citric acid cycle and contributing to the overall metabolism and energy balance in biological systems.

5 Must Know Facts For Your Next Test

1. Oxidative phosphorylation accounts for approximately 90% of the total ATP produced in aerobic respiration, making it a crucial step in energy metabolism.
2. The process occurs in the inner mitochondrial membrane, where the electron transport chain and ATP synthase are located.
3. Oxygen serves as the final electron acceptor in the electron transport chain, leading to the formation of water as a byproduct.
4. Proton pumping during electron transfer creates a proton motive force, which drives protons back into the mitochondrial matrix through ATP synthase for ATP production.
5. Inhibition of any component of oxidative phosphorylation can lead to decreased ATP production and increased production of reactive oxygen species, impacting cell health.

Review Questions

• How does oxidative phosphorylation integrate with other metabolic pathways to influence energy production?
  • Oxidative phosphorylation integrates with metabolic pathways like glycolysis and the citric acid cycle by utilizing NADH and FADH2 generated from these pathways. The high-energy electrons from these carriers are transferred through the electron transport chain, ultimately leading to ATP synthesis. This connection highlights how energy from food is transformed into a usable form (ATP) through a series of coordinated biochemical reactions.
• Discuss the role of the electron transport chain in oxidative phosphorylation and its significance in cellular respiration.
  • The electron transport chain plays a crucial role in oxidative phosphorylation by facilitating the transfer of electrons derived from NADH and FADH2. As electrons pass through a series of protein complexes, they release energy used to pump protons across the inner mitochondrial membrane, creating a proton gradient. This gradient is essential for driving ATP synthesis through chemiosmosis when protons flow back into the matrix via ATP synthase, highlighting its significance as a key step in cellular respiration for efficient energy production.
• Evaluate the impact of oxidative phosphorylation on cellular metabolism and how disruptions can affect cellular health.
  • Oxidative phosphorylation is central to cellular metabolism, providing the majority of ATP needed for various cellular functions. Disruptions in this process can lead to decreased ATP availability, impacting cell survival and function. For instance, if electron transport chain components are inhibited, it can result in reduced ATP synthesis and increased reactive oxygen species production. This imbalance can lead to cellular stress and potential cell death, emphasizing the importance of maintaining proper function within oxidative phosphorylation for overall cellular health.

Related terms

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

Chemiosmosis: The movement of ions across a selectively permeable membrane, which in oxidative phosphorylation refers to protons moving down their gradient to drive ATP synthesis.

ATP Synthase: An enzyme that utilizes the proton gradient established by the electron transport chain to convert ADP and inorganic phosphate into ATP.