B9.3 - anaerobic respiration

• When you exercise very hard

  Your heart rate and breathing rate increase to supply oxygen to the muscles.

  energy from the breakdown of glucose is transferred to muscle cells
• Explain Anaerobic respiration

  1. Glucose is broken down to produce energy without using oxygen

  2. Lactic acid is produced instead of carbon dioxide and water
• Anaerobic respiration

  Less efficient than aerobic respiration because glucose molecules are not fully broken down
• During anaerobic respiration, lactic acid is produced instead of carbon dioxide and water
• Less energy is transferred during anaerobic respiration compared to aerobic respiration
• Oxygen debt

  The amount of oxygen needed to convert lactic acid back to glucose
• Buildup of lactic acid


  Causes muscle fatigue making them work less efficiently
• Oxygen debt repayment

  Heart rate and breathing rate stay high after exercise to convert lactic acid back to glucose
• Plants and microorganisms can also respire anaerobically
• When plants respire anaerobically, they produce ethanol and carbon dioxide instead of lactic acid
• Some microorganisms produce lactic acid during anaerobic respiration, while others like yeast produce ethanol and carbon dioxide
• Fermentation

  The anaerobic respiration process in yeast cells that produces ethanol and carbon dioxide
• explain how lactic acid removed

  1. lactic acid is converted to glucose in the liver
  2. the glucose is broken down using oxygen which repays oxygen debt
• Word equation for anaerobic respiration in animals:

  Glucose ——> lactic acid ( energy transferred)
• Word equation for anaerobic respiration In plants and micoorgansims: Glucose + oxygen → ethanol + carbon dioxide