Liver Amino acids metabolism Iron storage Detoxification

INGESTION DIGESTION ABSORPTION ASSIMILATION EGESTION Taking in food Breakdown of complex food substances into smaller soluble food substances Digested food is absorbed Into body cells Absorbed food is use to provide energy or form new protoplasm Removal of undigested food 5 processes in digestion

Transport and utilization of absorbed foods How are the absorbed food products used by the body. Types of absorbed food products  Glucose  Amino acids  Fats

Previously we talked abt breaking down the proteins we ate Proteins are acted on by proteases in the stomach and small intestines to give you amino acids. Where do all these amino acids go?

The Liver, the Food Processor 1.The amino acids are transported to the liver through the hepatic portal vein. 2.This vein is connected to the small intestines

Liver and protein synthesis Many new proteins are synthesized in the liver 1.Our body need new protein molecules to function efficiently and effectively, like enzymes to digest food, hormones for growth 2.New proteins are synthesis for repair work. Like skin’s proteins are synthesized to replace old skin cells are shed away. 3.Some examples of protein names are albumins, globulins, and those essential for blood clotting such as fribrinogen.

Excess amino acids What if we eat too much proteins? Like in a buffet when we eat a lot of beef and prawns? Do excess prawns get pass out from your faeces?

Excess amino acids Prawns’ proteins All broken down to amino acids Excess amino acids Deamination

Amino acids  Structure:  central carbon  amino group  acidic group (Carboxyl)  R group (side chain)  variable group  gives unique chemical properties to the amino acid —N——N— H H C—OH || O R | —C— | H

Deamination —N——N— H H C—OH || O R | —C— | H Amino group Carbon residue Ammonia (toxic) Urea (non-toxic) glucose glycogen

Deamination —N——N— H H C—OH || O R | —C— | H Amino group Carbon residue

Liver in Protein metabolism Hepatic portal vein

Iron Storage Red blood cell worn out Need to be destroyed Haemoglobin is brought to the liver to be broken down (covered the next chapter on blood) Iron is recycled from the red blood cells and stored in the liver

Bile A fluid produced by the liver,  made up of water, salts, bile acids, cholesterol, and lecithin (a fatty acid).  stored in the gallbladder  discharged into the small intestine  No enzymes are found in bile!

1.Break down fat in the intestine into tiny globules that can be dissolved and suspended in water 2.Enlarges the surface area thus increasing the efficiency of fat digestion 3.Neutralises stomach acid and help to create optimum pH conditions for digestive enzymes in the small intestine Bile

Think about it…. Bile has a yellow-green or golden color..

Detoxification

Liver in alcohol metabolism Liver can break down 10cm 3 of alcohol in an hour AlcoholCarbon dioxide + Water + Energy What happens when you drink excessively?

Alcoholism Excessive consumption of alcohol damages the liver, resulting in cirrhosis (scarring of liver) and hepatitis (liver inflammation)

Recap on liver functions 1.Deamination of amino acids 2.Iron storage 3.Production of bile 4.Detoxication

More functions of livers? Coming soon!