2.4 cellular respiration

• Cellular respiration

  1. Glucose is broken down to produce ATP which is used as energy for cell functions

  2. Can be aerobic (with oxygen) or anaerobic (without oxygen)
• Mitochondria

  • Where most aerobic cellular respiration takes place
  • Often described as the powerhouses of the cell
  • Some cells like muscle cells have many thousands of mitochondria
• Anaerobic respiration

  Takes place in the cytoplasm of the cell
• Aerobic respiration

  1. Glucose and oxygen are broken down into water and carbon dioxide

  2. Energy is captured for storage as ATP (adenosine triphosphate)
• Anaerobic respiration

  1. Takes place without oxygen

  2. Following glycolysis, fermentation of lactic acid releases only 2 ATP molecules

  3. Inefficient process leading to fatigue and pain in muscle cells

  4. Can only provide short term supplementation to aerobic respiration

  5. Resulting lactic acid requires oxidation in the mitochondria
• Energy needs exceed ability of heart and lungs to provide oxygen


  Anaerobic respiration takes place instead
• Anaerobic respiration is complete

  Oxygen debt is created during exercise, which is why we continue to breathe deeply after exercise