energy systems

• ATP:

  • currency of all biological energy
  • only source of energy for movement
• ATP=


  energy stored (2-3 seconds worth)
• what does ATP stand for?

  adenosine triphosphate
• which bond in ATP is the high energy bond?


  the bond between the second and third phosphates
• what enzyme breaks down ATP?


  ATPase
• what type of reaction is ATP synthesis?

  exothermic reaction
• is ATP synthesis reversible or irreversible?

  reversible
• what are the three energy systems?


  • PC system
  • lactic acid/anaerobic system
  • aerobic system
• what is the energy continuum?

  the relative contribution of all three energy systems to the resynthesis of ATP (at the same time)
• PC system:

  • very high intensity
  • short duration

  e.g. javelin
• Lactic acid system:

  • high intensity
  • short duration

  e.g. 400m hurdles
• aerobic system:

  • moderate intensity
  • long duration

  e.g. marathon
• what % does the ATP/PC system work at?

  95%
• what is the yield of the ATP/PC system?


  1:1
• what is the energy source in the ATP/PC system?


  phosphocreatine
• where is phosphocreatine stored?

  sarcoplasm
• what are the benefits of the ATP/PC system?

  • maximal high energy
  • no harmful bi-products
  • no wait for CO2
• what are the limitations of the ATP/PC system?

  • duration 8-12 seconds
  • yield 1:1
  • limited source of creatine (limiting factor)
• what % does the anaerobic system work at?

  80-95%
• what is the yield of the anaerobic system?


  1:2
• what is the energy source in the anaerobic system?

  glycogen
• where is glycogen stored?

  in the liver as glucose
• what are the benefits of the anaerobic system?

  • no wait for CO2
  • high energy
• what are the limitations of the anaerobic system?

  • harmful bi-product produced (lactic acid - limiting factor)
  • insufficient yield (1:2)
  • short duration
• what % does the aerobic system work at?

  60-80%
• what is the yield of the anaerobic system?


  1:38
• what is the energy source of the aerobic system?

  glycogen
• what are the benefits of the aerobic system?

  • long duration (up to 2 hours)
  • no harmful bi-products
  • high yield (1:38)
• what are the limitations of the aerobic system?

  • O2 delay
  • moderate intensity
  • limiting factor - glycogen store
• when ATP levels fall...

  creatine kinase is stimulated
• explain the process of the aerobic system

  glycogen --glycolysis--> glucose-6-phosphate --2 ATP gained--> pyruvic acid --sufficient oxygen--> acetly-CO-A--> citric acid --> krebs cycle
• what is gained from the krebs cycle in the aerobic system?

  • 2 ATP
  • CO2 bi-product
  • hydrogen ions which undergo ETC and produce 34 ATP and water (sweat)
• explain the process of the anaerobic system

  glycogen --broken down in body--> glucose-6-phosphate--glycolysis -->pyruvic acid --LDH--> lactic acid (4mmol threshold)

  LDH = locate dehydrogenase
• what factors affect the energy system being used?

  • intensity
  • duration
  • fitness level