Aerobic and anaerobic respiration

• Aerobic respiration


  The chemical reactions in cells that use oxygen to break down nutrient molecules to release energy
• Aerobic respiration


  1. Glucose reacts with oxygen

  2. Releases carbon dioxide

  3. Releases water

  4. Releases energy
• Anaerobic respiration


  The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
• Anaerobic respiration is a less efficient process than aerobic respiration because it releases much less energy per molecule of glucose
• Anaerobic respiration in yeast


  1. Glucose is converted to carbon dioxide

  2. Glucose is converted to alcohol

  3. Releases energy
• Oxygen debt


  The oxygen required to break down the accrued lactic acid after a period of high intensity exercise
• Removing oxygen debt after exercise


  1. Heart rate remains elevated

  2. Breathing rate and depth remain elevated

  3. Provides additional oxygen for aerobic respiration of lactic acid in the liver
• Anaerobic respiration converts glucose to lactic acid which accumulates in the muscle cells and blood, causing discomfort and muscle fatigue
• Only when resting can sufficient oxygen be delivered to break down the lactic acid and for the muscles to regain their function
• Lactic acid is broken down into carbon dioxide and water by aerobic respiration in the liver
• Anaerobic respiration occurs in yeast cells and muscle cells during vigorous exercise
• Aerobic respiration is a more efficient process than anaerobic respiration
• Anaerobic respiration releases much less energy per molecule of glucose compared to aerobic respiration
• Yeast is added to a sugary solution made from Hops and Grains, it converts some of the sugars to alcohol and also releases carbon dioxide which makes the drinks fizzy
• During high intensity exercise, oxygen cannot be delivered quickly enough for the muscle cells to respire aerobically, so anaerobic respiration makes up the deficit
• The balanced chemical equation for aerobic respiration is C6H12O6 + 6O2 -> 6CO2 + 6H2O
• The balanced chemical equation for anaerobic respiration in yeast is C6H12O6 -> 2C2H5OH + 2CO2