metabolism

• what is metabolism?

  • the metabolism of an organism is the sum of all of the chemical reactions that take place in the body or a cell
• metabolic examples

  • glucose -> starch
  • glycogen -> cellulose
  • formation of lipids from a molecule of glycerol and three fatty acid molecules
  • use of glucose and nitrate ions to form amino acids
  • respiration
  • photosynthesis
  • breakdown of proteins in liver to form urea for excretion in urine via the kidneys
• what is the role of the liver?

  • detoxifying poisonous substances
  • passing the breakdown products into the blood so they can be excreted in the urine via the kidneys
  • breaking down old worn out blood cells and storing iron until it is needed to synthesise more blood cells
• how does the liver remove lactic acid?

  • blood flowing through muscles transports lactic acid to the liver where it is converted back into glucose