Aerobic system

• Aerobic glycolysis


  Takes place in muscle sarcoplasm
• Presence of O₂


  Prevents build up of lactic acid
• O₂


  Allows pyruvic acid to combine with coenzyme A which allows the Krebs cycle to take place
• Aerobic glycolysis


  1. Glucose

  2. Pyruvic acid

  3. Acetyl CoA

  4. Krebs cycle
• Krebs cycle


  1. Acetyl CoA combines with Oxaloacetic Acid = Citric acid

  2. CO₂ is produced and removed via lungs

  3. Hydrogen atoms removed (oxidation)

  4. Energy produced to resynthesise 2 mols of ATP

  5. Oxaloacetic acid is regenerated
• Electron Transport Chain


  1. Hydrogen atoms from Krebs cycle are carried along ETC along the cristae folds

  2. Split into electrons and H+ ions

  3. Carried by NADH, release energy to resynthesise 30 ATP

  4. Succinate by ADP release enough energy to resynthesise 2 ATP
• Contrasingame & ATP/ETH / coenzyme A lipase


  Breakdown of fuel sources
• ATP yield


  38 ATP
• Aerobic glycolysis


  • Occurs during low-moderate intensity activities
  • Enables energy production when levels of oxygen are sufficient
• Aerobic energy production


  • Up to 2 hours - mix of glycogen and FFA
  • FFA become predominant after 2 hours
• Byproducts of aerobic energy production are CO₂ and H₂O
• Intensity


  • Low/medium intensity - submaximal
• Duration


  • 3 minutes onwards