The liver

• Function of the liver= excretion (the removal of products of metabolism from the body)

  • Produces bile= emulsifies fats, neutralises conditions in small intestine.
  • Stores glycogen.
• Hepatic artery supplies liver with oxygenated blood from the heart.
• Hepatic portal vein supplies liver with nutrients from the digestives system (glucose, amino acids)
• Hepatic vein takes blood from the liver to the heart.
• Sinusoid= pool of blood, where blood from the hepatic artery and hepatic portal vein mix.

  • Substances are transferred into and out of the hepatocytes
• Kuffer cell= white blood cell in the liver, destroys pathogens.
• transamination= conversion of one amino acid into another.

  • Importance= diet does not always contain the required balance of amino acids.
• Deamination= removal of an amine group from a molecule.

  • Body cant store amino acids or proteins.
  • Covert into ammonia which is very toxic and the into urea which is then secreted.
• Ornithine cycle

  • Ammonia+ carbon dioxide+ ornithine= citrulline (water also produced due to condensation reaction)
  • Citrulline+ ammonia= arginine (water)
  • Arginine+ water= urea+ ornithine.
• Detoxification

  • Hydrogen peroxide= water and oxygen (by enzyme catalase)
  • Ethanol= ethanal+ ethanoate (by enzyme dehydrogenase)