Metabolism and the liver

• the metabolism of an organ is the sum of all the reactions that take place in the body
• there are hundreds of thousands of metabolic reactions; the most common include:

  • conversion of glucose to starch, glycogen and cellulose
  • formation of lipids from a molecule of glycerol and fatty acids
  • use of glucose and nitrate ions to make amino acids—form proteins
  • respiration and photosynthesis
  • breakdown of excess proteins in liver to form urea for excretion in the urine by the kidneys
• the liver is a large organ which carries out many metabolic functions
• the liver; detoxifies substances such as alcohol, passing the breakdown of products into the blood so they can be extracted by the kidney, breaking down old blood cells
• the liver converts lactic acid back to glucose
• the oxygen debt is repaid once the lactic acid is converted back to glucose and the glucose is respired
• excess glucose can also be stored in the liver in the form of glycogen