Respiration

• Respiration


  A chemical reaction which occurs in all living cells, releasing energy from glucose
• Respiration is not the same as breathing or ventilation
• Aerobic respiration


  Glucose + oxygen → carbon dioxide + water
• Aerobic respiration


  • Occurs with oxygen
  • Releases more energy but more slowly
• Anaerobic respiration


  Glucose → lactic acid
• Anaerobic respiration


  • Occurs without oxygen
  • Releases less energy but more quickly
• During vigorous exercise


  Anaerobic respiration occurs as cells may not have enough oxygen
• Lactic acid builds up in muscles causing pain and tiredness, which can lead to a cramp
• After muscle contraction, people continue to breathe deeply and quickly for a short period (excess post-exercise oxygen consumption or EPOC)
• During EPOC, lactic acid reacts with oxygen to form carbon dioxide and water, and releases the rest of the energy originally in the glucose
• Comparison of aerobic and anaerobic respiration

  • Reactant(s)
  • Product(s)
  • Rate of reaction
  • Energy released
• Aerobic respiration is slow but releases more energy, anaerobic respiration is fast but releases less energy