The Role of Oxygen in Respiration

Describe the role of oxygen in respiration

  • Oxygen has two primary roles in cellular respiration:
    1. Produce energy (captured in the form of ATP) as it moves through the respiratory chain.
    2. Accept electrons and hydrogen in the ETP, forming H2
  • Oxygen is an oxidiser and plays a role in the oxidation/reduction reactions that release energy.
  • Glycolysis is the first step, where glucose is converted to pyruvic acid in the cell cytoplasm. This is a rapid process; however, it produces only a small amount of ATP.
  • Pyruvic acid is then converted to either acetyl CoA if oxygen is readily available for oxidation to CO2and H2O, or to lactic acid if oxygen is unavailable.
  • If the oxygen supply can meet demands, pyruvic acid will be converted to acetyl-CoA and then carbon dioxide and water. This is known as aerobic respiration because oxygen is required for this series of reactions. Aerobic respiration is slow, but releases large amounts of ATP.