Respiration

• Aerobic respiration uses oxygen.
• Anaerobic respiration does not use oxygen.
• Anaerobic respiration is less efficient, occurs in the cytoplasm and a waste product in animals is lactic acid.
• Aerobic respiration is more efficient, occurs in the mitochondria and the waste products in animals are water and carbon dioxide.
• What do we use the energy for from respiration?

  Homeostasis, movement and building activities (growth and repair)
• The aerobic respiration equation in animals is:

  Glucose + oxygen —> carbon dioxide + water + energy
• The anaerobic respiration equation in animals is:

  Glucose —> lactic acid + energy
• What is oxygen debt?

  The amount of oxygen required to remove lactic acid.
• Respiration in yeast:

  Glucose —> carbon dioxide + ethanol + energy
• What is metabolism?


  Metabolism is the process by which the body converts food and drink into energy.
• Blood transports lactic acid to the liver where it is converted back into glucose.
• Metabolism includes:

  • conversion of glucose to starch, glycogen and cellulose
  • the formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids
  • the use of glucose and nitrate ions to form amino acids which in turn are used to synthesise proteins
  • respiration
  • breakdown of excess proteins to form urea for excretion