Zusammenfassung der Ressource
The liver
- Detoxification of alcohol
- Takes place in the smooth
endoplasmic reticulum of the
Hepatocytes
- Ethanol molecules are
small and fat soluble so
can pass through the
phospholipid bilayer into
cells.
- 1. Ethanol is
converted into
ethanal by
ethanol
dehydrogenase.
- 2. Ethanal is converted
into ethanoic acid by
ethanal dehydrogenase.
- 3. Ethanoic acid in
converted into
Acetlycoenzyme A
- Fatty liver----
NAD is
required to
oxidise fatty
acids. If too
much alcohol
is consumed,
there is not
enough NAD
to do so. As a
result, fatty
deposits build
up in the liver.
- Cirrhosis -----
Toxins in
alcohol damage
the
hepatocytes.
Damaged
hepatocytes
are replaces by
fibrous tissue.
The liver is not
able to
effectively
carry out its
function.
- Blood supply
- Receives oxygenated
blood from the hepatic
artery which branches off
the Arota.
- The hepatic portal vein carries blood
from the digestive system so that the
kidneys can control the levels of
compounds ingested.
- Blood is carried by the
hepatic vein back to the
vena cava
- Functions
- Control of blood glucose levels
- synthesis of
cholesterol and
plasma proteins
- Detoxification of alochol
- Excretion
- The removal of metabolic
waste from the body. This is
the unwanted substances
produced in cell chemical
reactions.
- Excretion of CO2
- Binds with haemoglobin to from
carbaminohaemoglibin. This has a
lower affinity for O2.
- Dissolves in plasma and
combines with H2O to
form carbonic acid.
- This dissociates into
HCO3- and H+.
- This increases the acidity of the blood.
- Leads to breathing difficulty,
headaches, drowsiness, tremors
and confusion.
- Excretion of Nitrogenous compounds
- Amino acids cannot be stored so they are
Deaminated in the liver. This produces
ammonia which is highly toxic. It must be
converted into urea.
- The remaining Keto acids
are respired or turned
into a carbohydrate or
lipid for storage.
- The Ornitine cycle
- 1. Ornitine + NH3 + CO2 ----> Citrulline + H2O
- 2, Citrulline + NH3 -----> Arginine + H2O
- 3. Arginine + H2O -----> Urea + Ornithine