(13) excretion in humans

• carbon dioxide is excreted through lungs
• kidney excrete urea, excess water and ions
• glomerulus: ultrafiltration

  • filtration from the blood of water, glucose, urea and ions
  • has high blood pressure and forces molecules into bowman’s capsule
• nephron: selective reabsorption 

  • reabsorb all glucose, some ions and most water back into blood
  • forms urine containing: urea, excess water and excess ions
• liver: assimilation of amino acids by converting them into protein

  • urea is formed by excess amino acids
  • deamination is the removal of nitrogen containing part of amino acids to form urea
  • urea is toxic