Respiration. pg 29

• Respiration is the process of transferring energy from glucose, which happens constantly in every living cell. Some of the energy is transferred by heat.
• The energy transferred by respiration can't be used directly by cells, so it's used to make a substance called ATP.
• ATP stores the energy needed for many cell processes.
• When a cell needs energy, ATP is broken down and energy is released.
• Aerobic respiration needs oxygen.
• Aerobic respiration is the most efficient way to transfer energy from glucose. It produces lots of ATP - 32 molecules per molecule of glucose.
• glucose + oxygen -----> carbon dioxide + water
• C6H12O6 + 6O2 -----> 6CO2 + 6H2O
• Anaerobic respiration doesn't use oxygen at all.
• Anaerobic respiration releases much less energy per glucose molecule than aerobic respiration - just 2 molecules.
• In anaerobic respiration, the glucose is only partially broken down, and lactic acid is also produced.
• Lactic acid builds up in the muscles - it gets painful and causes cramps.
• Anaerobic respiration in animals:

  
  

  glucose -----> lactic acid (+ energy)
• Anaerobic respiration in plants:

  glucose ------> ethanol + carbon dioxide (+ energy)