Energy systems

• What’s so special about ATP to humans?

  It’s the only usable form of chemical energy in the human body
• What does ATP consist of?

  Adenosine, 3 phosphate and a ribose sugar
• How long does ATP last for?

  2 - 3 seconds
• What is the Sarcolemma?

  The cell membrane of the muscle cell
• What is the sarcoplasm?

  The cytoplasm of a muscle cell. Contains ATP, glycogen and Phosphocreatine.
• What is Glycolysis?

  The breakdown of glucose into pyruvate producing energy for re-synthesis of ATP
• What are the three energy systems?

  • ATP-PC system
  • Anaerobic glycolytic system
  • aerobic system
• What are the two parts of the ATP-PC system?

  1. PC -> P + C + energy
  2. ADP + P + energy -> ATP
• What and why are the ATP-PC reactions referred to as?

  A coupled reaction because

  1. Step 1 is Exothermic
  2. Step 2 is Endothermic
• What happens to PC after it is used?

  Creatinine migrates from cells into blood, into the kidneys and then excreted as urine
• What are some disadvantages of using the ATP-PC system?

  • One molecule of PC means only one molecule of ATP re-synthesized
  • Stores only last for 5 - 8 seconds of high-intensity exercise
  • PC can only be re-synthesized in presence of oxygen
• What is the facilitating enzyme for ATP?

  ATPase
• Where is the high energy bond in ATP?

  Between the second and third phosphate groups.
• What do the energy systems used primarily and only do?

  Re-synthesize ATP
• What enzyme breaks down Phosphocreatine?

  Creatine kinase
• Where does the ATP-PC system re-synthesize ATP?

  In the Sarcoplasm
• Where does the Anaerobic glycolytic system resynthesize ATP?

  In the sarcoplasm
• What enzyme is activated when PC stores are low and what does it do?

  Glycogen Phosphorylase

  It breaks down muscle glycogen converting it to glucose
• How is glucose broken down?

  Through glycolysis and using the enzyme phosphofructokinase

  This breaks it down into :

  • 2 Pyruvic acid molecules
  • 4 Hydrogen ions
• What happens after the break down of glucose due to there being no available Oxygen?

  Hydrogen ions build up creating an acidic environment which denatures enzymes causing muscle pain
• What is pyruvic acid converted to during the end stages of anaerobic glycolytic system?

  It is converted to lactic acid via the enzyme Lactate dehydrogenase
• How long can the anaerobic glycolytic system be sustained?

  10 seconds - 3 minutes
• What are some of the advantages of the ATP-PC system?

  • No oxygen required
  • Energy is released rapidly
  • Excellent for short / high intensity events (e.g 100m sprint)
  • PC can be resynthesized quickly (50% in 30 secs and 100% in less than 4 mins)
  • System can be extended through creatine supplements
• How much energy does glycolysis release?

  Enough energy to resynthesize 2 ATP molecules
• What are the advantages of the anaerobic glycolytic system?

  • ATP can be resynthesized quickly
  • Lasts longer than the ATP-PC system
  • The lactic acid produced can be converted back into glycogen or used as fuel via oxidation into carbon dioxide and water
  • Its useful for sprint finishes
• What are the disadvantages of the anaerobic glycolytic system?

  • The by-product of Lactic acid which accumulates creating an acidic environment which denatures enzymes preventing them from increasing rate of reaction
  • Only a small amount of energy is released from glycogen under anaerobic conditions