A bit of Liver Phys Flashcards
How is alcohol broken down?
• Alcohol =Alcohol Dehydrogenase=> Acetaldehyde == Acetaldehyde Dehydrogenase=> Acetate ==> CO2 and H2O
Alcohol can be broken down into Acetate, which Can be used in The Krebs cycle as Acetyl CoA.
However its mostly broken down into Water and CO2 ==> Can lead to Acidosis
Outline bilirubin breakdown
Haemoglobin= Haem = Biliverdin, (Hemoxygenase) Reduced to Unconjugated Bilirubin,
travels In blood to bound to albumin to liver, undergoes Glucuronidation into Conjugated Bilirubin, (by enzyme glucuronosyltransferase)
released in Bile and becomes Urobilinogen due to gut bacteria ,
90% of Urobilinogen becomes Stercobilin (faeces) and 10% becomes Urobilin (recycled back to bile or urinated out)
What do Pancreatic polypeptide/(PP) Cells in the islet of langerhans secrete?
Pancreatic polypeptide (1)
bile salts that are produced in the liver are needed to produce what vitamin? What does this vitamin do?
The liver produces bile salts that are essential for the absorption of vitamin K
(1)
- Clotting factors 10, 9, 7 and 2 (1) rely on vitamin K for their synthesis
Explain the process of
ketogenesis in the liver.
High rates of fatty acid oxidation result in large amounts of acetyl-CoA
production that exceed the capacity of the Krebs cycle
- 2 molecules of acetyl-CoA are converted into acetoacetyl-CoA by the enzyme thiolase
- Acetoacetyl-CoA is converted into acetoacetate (
- This is then converted into b-hydroxybutyrate by b-hydroxybutyrate
dehydrogenase and acetone spontaneously (1)
What ligament divides the liver into anatomical left and right lobes?
Falciform ligament.
What is oxidative deamination?
Amino acid catabolism that results in the liberation of the amino group as free ammonia.
outline transamintaion
- transfer of an alpha-amino group from an amino acid (eg Alanine) to a keto-acid (eg pyruvate) to form and alpha- keto-acid (eg a-ketoglutarate)Alpha Ketoglutarate readily accepts Amine from Alanine
Forms Glutamate + Pyruvate - can be used in Gluconeogenesis, and aerobic respiration
Under enzyme Alanine Aminotransferase: (found in the cytosol/matrix and the mitochondria)
outline oxidative deamination
glutatmate + h2O (with glutamiate dehydrogenase ) = alpha ketoglutarate and Ammonia
Outline glucose alanine cycle
- Transamination in the Muscles
Glut + Pyruvate ==> Alanine and AKG.- Alanine produced is transported via
Blood to liver - Transamination in liver -
Alanine + AKG ==> Glutamate and Pyruvate - Glutamate will then undergo Oxidative Deamination to get rid of excess NH3 In the Urea Cycle.
(Glutarate + H2O ==> a- Ketoglutarate and Ammonia)
Pyruvate will become Glucose in Gluconeogenesis
- Alanine produced is transported via
Outline the urea cycle
ARGININE, ==> Urea – ORNITHINE – (ammonia + CO2 ) = CITRULLINE + ammonia = ARGININE
What does
a) Hepatic Lipase
b) lipoprotein lipase
Do?
LIPOPROTEIN LIPASE -
Hydrolyses Triglycerides in Lipoproteins (Chylomicrons and VLDLs) into 2 free fatty acids and 1 glycerol molecule
Hepatic Lipase
• Expressed in liver and adrenal glands
Converts IDL into LDL, thereby packaging it with more triglycerides to be released into the body
Outline ketogenesis
2x Acetyl CoA –> Acetoacetyl CoA (thiolase)
Acetoactyl CoA ===> Acetoacetate
Acetoacetate ===> b-hydroxybutarate and acetone
Where is vit a stored?
ito cells in space of disse
what is vit K needed for
clotting factor produciton ,10.9.7.2
