Function of the liver

HideShow resource information
View mindmap
  • Functions of the liver
    • Protein metabolism:
      • Production of 3 blood proteins: Fibrinigen, albumin, globulins. Production of urea - linked to deamination.
      • TRANSAMINATION = Convert 1 amino acid to another amino acid. DEAMINATION = Removing excess amino acids.
      • During DIGESTION, proteins are HYDROLYSED into AMINO ACIDS and transported to the LIVER along HEPATIC PORTAL VEIN.
      • Excess amino acids cannot be stored in the liver. Excess undergo DEAMINATION and are also converted into GLUCOSE and TRIGLYCERIDES.
      • TRANSAMINATION occurs in the liver. Conversion of 1 amino acid to another - non-essential amino acids are synthesised.
    • Stores vitamins and minerals, synthesis and regulation of cholesterol, breaks down hormones, produces urea.
    • Produces BILE, amino acids converted to GLUCOSE, protein, lipid and carbohydrate METABOLISM, DEAMINATION/ TRANSAMINATION.
    • Formation of urea:
      • Produced by liver from excess amino acids. Converted into urea by deamination or urea formation. Transported to KIDNEYS in blood where it is EXCRETED.
    • Deamination:  AMINE group of amino acids REMOVED. AMMONIA formed - highly SOLUBLE + TOXIC so must be removed. KETO acid enters respiration to release ENERGY or STORED as fat.
    • ORNITHINE CYCLE:
      • Ammonia converted into LESS soluble + LESS toxic UREA. Urea travels in blood to KIDNEYS Ornithine cycle requires energy from ATP.
      • ORNITHINE --> CITRILLINE --> ARGININE
      • Ornithine: Ammonia + CO2 in, H20 out.
      • Citrilline: Ammonia in, H20 out.
      • Arginine: H20 in, urea out.
      • O = Amino group + HYDROGEN is removed to form AMMONIA and  a KETO ACID.
      • C = Highly TOXIC ammonia enters ornithine cycle + converted to UREA. Excess amino acids cannot be stored and undergo DEAMINATION in the liver.
      • A = Keto acid either enters RESPIRATORY pathway and generates ATP or it is converted into CARBOHYDRATES or FATS.
    • Detoxification: Liver can detoxify many compounds. Can take place by OXIDATION, REDUCTION or METHYLATION  of toxins.
    • Detoxification of ALCOHOL, ANTIBIOTICS, STEROID HORMONES e.t.c often by action of ENZYMES.

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cellular processes and structure resources »