Respiration

• Respiration in cells can take place aerobically (using oxygen) or anaerobically (without oxygen) to transfer energy
• Aerobic respiration

  Glucose + Oxygen -> Carbon dioxide + Water

  C6H12O6 + 6O2 -> 6CO2 + 6H2O
• Aerobic respiration takes place continuously in both plants and animals in the mitochondria
• The energy released from respiration can be used for:-

  Muscle movement

  Maintaining body heat

  In plants - to build up sugars, nitrates, and other nutrients into amino acids which are then built up into proteins

  Active transport
• During excercise:-

  Heart rate increases, increasing blood flow to the muscles

  Rate and depth of breathing increases

  Glycogen stored in the muscles is converted back to glucose

  
  

  These changes increase the supply of glucose and oxygen and increase the rate of removal of carbon dioxide from the muscles.
• Anaerobic respiration

  Glucose -> Lactic acid + Energy

  C6H12O6 -> 2C3H6O3 + 2ATP
• Lactic acid is produced in anaerobic respiration which stops our muscles from contracting thus they become fatigued
• Blood flowing through the muscles eventually removes the lactic acid
• Oxygen debt is the excess oxygen needed to break down/oxdise the lactic acid into carbon dioxide and water to allow muscles to return to normal

  Lactic acid + Oxygen -> Carbon dioxide + Water
• Much less energy is transferred in anaerobic respiration than during aerobic respiration
• Fermentation is anaerobic respiration in plants and yeast cells

  Glucose -> Ethanol + Carbon dioxide
• Anaerobic respiration is the incomplete breakdown of glucose which causes a build up of lactic acid