Aerobic Respiration

  • Aerobic respiration refers to the process of releasing energy from glucose, or similar molecules, in the presence of oxygen.
  • The chemical reaction for aerobic respiration is as follows: Glucose + Oxygen -> Carbon Dioxide + Water + Energy (as heat and ATP)
  • ATP, or Adenosine Triphosphate, is the main energy source used by cells. It is produced in large quantities during aerobic respiration.
  • Aerobic respiration occurs in small structures within cells called mitochondria.
  • The whole process is divided into four stages: Glycolysis, Link Reaction, Krebs Cycle and Oxidative Phosphorylation.
  • Glycolysis occurs in the cytoplasm and breaks down glucose into two 3-carbon molecules called pyruvate. This process generates a small amount of ATP and also produces reduced NAD.
  • The Link Reaction takes place in the mitochondria where pyruvate is decarboxylated to form a 2-carbon molecule and a molecule of carbon dioxide.
  • The Krebs Cycle, also taking place in the mitochondria, utilises the 2-carbon molecule from the Link Reaction to produce further reduced NAD, reduced FAD and ATP. Carbon dioxide is also a byproduct.
  • Oxidative Phosphorylation is the final stage. It is here that the bulk of ATP is produced. The energy from reduced NAD and FAD is used to add inorganic phosphate to ADP to form ATP. Oxygen acts as the final electron acceptor and along with the hydrogen from the reduced NAD and FAD, forms water.
  • The whole process of aerobic respiration releases around 32 molecules of ATP per molecule of glucose. This energy is employed for various functions within the cell and body.
  • Since aerobic respiration requires oxygen, it is a factor limiting the rate of respiration. If oxygen levels are low, anaerobic respiration may occur instead.
  • Carbon dioxide and water, the waste products of respiration, are removed from the body by the respiratory and urinary systems respectively.
  • The heat produced from aerobic respiration contributes to maintaining our body temperature.

Remember to make use of diagrams and flowcharts to better understand the process and pathways involved in aerobic respiration.