energy system

• ATP: (adenosine triphosphate) main energy source that cells use for most of their work
• ADP + P + energy = ATP: Equation for resynthesise of ATP
• ATP-PC system: energy system producing ATP during high intensity, short duration exercise. Phosphocreatine decomposes and releases large amount of energy used to construct ATP. Provides energy for muscle contraction for up to 10 seconds.
• high energy bond: potential energy stored between 2nd and 3rd phosphate of ATP
• Anaerobic


  working without oxygen
• Aerobic


  working with oxygen
• exothermic reaction: A chemical reaction that releases energy in the form of heat
• endothermic reaction


  a chemical reaction that requires heat
• phosphocreatine (PC): A chemical compound stored in muscle, which when broken down aids in manufacturing ATP.
• ATPase: -enzyme that breaks ATP into ADP.

  -breaks bond between 2nd and 3rd phosphate
• Creatinekinase


  enzyme that breaks down phosphocreatine (PC)
• Lactic Acid System: Anaerobic energy system. Also called anaerobic glycolysis or glycolytic system. Fuel source = carbs as glucose and glycogen. Duration = 10 sec- 3min. Recovery time =20 mins- 2 hrs. By-products = lactic acid. Effort = moderate. Cause of fatigue = lactic acid accumulation.
• Lactic acid system becomes dominant energy system: after 10secs of high intensity exercise when PC and ATP stores are depleted
• sarcoplasm: site of reaction for ATP stores/ ATP-PC system/ lactic acid system/ aerobic glycolysis
• mitochondria matrix


  site of reaction Kreb's cycle
• Cristae of mitochondria: site of reaction electron transport chain (ETC)
• Acetyl CoA: Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.
• Phosphocreatine (PC) store duration: 8-10 seconds worth of PC stored in the body
• ATP-PC duration


  0-10 seconds
• Lactic acid system duration

  10secs - 3 mins
• Aerobic system duration


  3 min +
• ATP-PC recovery time: 98% 3 mins

  75% 1 min

  50% 30secs
• Lactic acid system recovery time

  8 minutes
• Aerobic System recovery time: 2-48 hours, depending on activity duration
• 1:1


  ATP-PC energy yield
• 1:2


  Lactic acid energy yield
• 1:38


  Aerobic system energy yield
• 34 ATP molecules are resynthesised during: electron transport chain energy yield
• 2 ATP molecules are resynthesised during: Glycolysis and krebs cycle energy yield
• Lactic acid system process: -when glucose is not immediately needed, it is stored as glycogen in muscles and liver.

  -glycogen phosphorylase (GPP) breaks glycogen down into glucose.

  - glucose is then used to breakdown into energy

  -ATP can then be resynthesised.
• lactate dehydrogensase (LDH): enzyme that converts pyruvic acid to lactic acid without oxygen present
• lactic acid: harmful by-product of anaerobic glycolysis that causes fatigue
• Aerobic glycolysis: -process of the breaking down of glucose into pyruvic acid in the presence of oxygen via phosphofructokinase (PFK)

  -resynthesizes 2 ATP molecules
• glucose/ glycogen / triglycerides: Fats/ fuel source of aerobic systems
• Water (H2O), Carbon Dioxide (CO2): By-products of the aerobic system
• Krebs Cycle (Citric Acid Cycle): - Occurs in the mitochondria matrix

  -Pyruvic acid produced previously is converted into acetyl coenzyme A in the mitochondria.

  - carbon compounds combine with oxaloacetic acid to make citric acid.

  - 2 ATP resynethesised.

  -NAD molecules bind with hydrogen to create NADH.

  - NADH carries through into the the ETC, in the cristae of mitochondria
• NADH: -An energy-carrying coenzyme produced by glycolysis and the Krebs cycle.

  -NADH carries energy to the electron transport chain, where it is stored in ATP.
• electron transport chain (ETC): - NADH moved to cristae of mitochondria.

  - the electron transport chain (ETC) takes hydrogen from the NADH and oxygen.

  - these combine to release energy to resynthesise 34 molecules of ATP.

  - H2O and CO2 are a by-product.
• Recovery process opportunity: stopping exercise/ low intensity/ bouts of inactivity to allow aerobic activity to repay the oxygen debt.
• Excess post-exercise oxygen consumption (EPOC): - O2 deficit that must be paid back after rest.

  - Deficit comes from energy we used when working anaerobic