Aerobic (oxidative) Respiration

Aerobic (oxidative) Respiration

1. Glycolysis

   • Glycogen (C6H12O6)
     • Glucose-6-phosphate
       • pyruvic acid
         • Acetyl-coenzyme-A
         • Only converted to acetyl-coenzyme-A if sufficient oxygen is present
   • OCCURS IN THE SARCOPLASM
   • Bodies preferred energy pathway

2. Krebs cycle

   • Acetyl-coenzyme-A
     • Citric acid
       • Oxidated
         • removal of H+ atoms, which enter the electron transfer system
   • 2 ATP
   • Carbon Dioxide
     • The removal of H leaves C and O2 whcih combine to form CO2
       • carried to lungs and breathed out
   • OCCURS IN THE MATRIX

3. Electron Transfer system

   • H+ ions
     • Water
   • 34 ATP
     • Most efficient source of energy in the body
   • Combines with electrons
     • Water
   • OCCURS IN THE CRISTAE

4. Beta-Oxidation

   • Fat and proteins can be metabolised under aerobic conditions
     • It forms water, carbon dioxide and energy for ATP resynthesis.
   • Fats are stored at triglycerides
     • Broken down to glycerol and free fatty acids (FFAs)
       • before undergoing beta-oxidation
   • After beta-oxidation has occurred the fatty acids can enter the Krebs cycle, and follow the path of glycogen
   • More energy can be obtained from 1 mole of fatty acid than 1 mole of glycogen
   • Fatty acids become the preferred fuel after about 20 mins of sub-maximal activity

5. Significantly more ATP can be resynthesised under aerobic conditions.

6. The body has substantial stores of muscle glycogen and triglycerides to enable exercise to last for several hours

7. Oxidation of glycogen and fatty acids do not produce any fatiguing bi-products

8. transport of fatty acids is slow and requires about 15% more O2 than what is required to break down the same amount of glycogen

9. When glycogen stores are depleted the body attempts to metabolise fatty acids , however muscle spasms may result from this