Functions of the Liver Flashcards
(27 cards)
What are the 9 functions of the liver?
-Detoxification of alcohol/prescribed drugs
-Removing bacteria (by kupffer cells) and other toxins
-Breaks down excess amino acids
-Makes bile and cholesterol
-Stores glycogen (helps regulate blood glucose concentration)
-Breaks down old RBC’s (kupffer cells and Hb (hepatocytes
-Breaks down lactic acid (lactate)
-Breaks down hormones eg insulin
-Stores vitamin A,D and B12
What are the 3 main functions to know about?
-Detoxification of alcohol/prescribed drugs
-Breaks down excess amino acids
-Stores glycogen to help regulate blood glucose concentration
What happens when there is an increase in blood glucose concentration?
-Insulin is released from beta-cells of islets of Langerhans in pancreas
-Causes liver and muscle cells to take up excess glucose and convert it to glycogen for storage
What is the process of glucose being converted in glycogen called?
Glycogenesis
What happens when there is a decrease in blood glucose concentration?
-Glucagon from alpha-cells of islets of Langerhans in pancreas
-Glycogen is hydrolysed (broken down) into glucose which is then released into the blood
What is the process of glycogen being hydrolysed into glucose called?
Glycogenolysis
What happens to excess amino acids?
Breakdown or converted
What happens if amino acids are converted?
Changed into different amino acids (one of 12 non-essential amino acids only)
What is it called when an amino acid is changed into a different amino acid?
Transamination
How does the breakdown of amino acids happen?
In 2 steps
-deamination
-ornithine cycle
What is deamination?
Removal of amine group containing N and produces keto acid and ammonia
What is the process of deamination?
See notes
Why is ammonia harmful?
Highly toxic and soluble
What is the first product of deamination?
Keto Acid
Where does this keto acid go?
Krebs cycle which is part of respiration to release energy/ATP
What is the Ornithine Cycle?
Ammonia +CO2 –> Urea
What is good about urea over ammonia?
Less toxic and less soluble
Where does urea go?
Into blood plasma, kidneys filter urea out of blood and urea is then excreted in urine
What is detoxification?
Breaking down toxic products
What is the first example of detoxification in the liver?
Hydrogen peroxide which is produced as a by-product by many metabolic reactions
How is hydrogen peroxide detoxified?
2 H2O2 –> 2 H20 + O2
Catalyse is what carries out this reaction which is the fastest working enzyme in the body
What is the second example of detoxification in the liver?
alcohol/ethanol
How is alcohol/ethanol detoxified?
See notes
What is NAD also used for?
To break down lipids
