Aerobic Respiration

Aerobic Respiration - Fundamentals

  • Aerobic respiration is a process wherein cells break down glucose in the presence of oxygen to release energy.
  • It’s termed aerobic because oxygen from the air (hence ‘aero’) is a key requirement for the process.
  • The overall chemical reaction of aerobic respiration can be summarized as: C6H12O6(glucose) + 6O2(oxygen) → 6CO2(carbon dioxide) + 6H2O(water) + energy.
  • The energy produced in this process is mainly stored in molecules called adenosine triphosphate (ATP).
  • The energy also aids in maintaining constant body temperature in warm-blooded animals.

Where does Aerobic Respiration occur?

  • Mitochondria within the cells is the primary site where aerobic respiration happens.
  • Glucose, the primary fuel source, is transported to the cells’ interior via the bloodstream.
  • Oxygen needed for the process, is conveyed to the cells by the respiratory system.

Stages of Aerobic Respiration

  • Aerobic respiration process is comprised of four steps: glycolysis, link reaction, Krebs cycle, and the electron transport chain.

  • Glycolysis: This step occurs in the cytoplasm where one glucose molecule (6 carbons) gets converted into two molecules of pyruvate (3 carbons each), generating 2 ATPs in the process.

  • Link reaction: Pyruvate is transported into the mitochondria where it is converted into Acetyl-CoA with the release of carbon dioxide.

  • Krebs cycle: This cycle happens in the mitochondrial matrix, where Acetyl-CoA is further broken down to release carbon dioxide, and generate energy in the form of ATP, NADH and FADH2.

  • Electron transport chain: This is the final stage where NADH and FADH2 are used to produce a large amount of ATPs. Oxygen acts as the final electron acceptor to help produce water as the end product.

Importance of Aerobic Respiration

  • Energy production: Aerobic respiration is crucial for all energy demanding processes within an organism.
  • Carbon dioxide production: The production of carbon dioxide, a waste product of aerobic respiration, is vital because it is used in plants for photosynthesis.
  • Water production: Another waste product, water, is essential for maintaining bodily functions and hydration status.

Aerobic vs Anaerobic Respiration

  • Unlike anaerobic respiration, aerobic respiration breaks down glucose completely, yielding more ATP (energy), and producing water and carbon dioxide as waste materials.
  • However, aerobic respiration requires oxygen and is slower compared to anaerobic respiration.