Transcript Liver funtions part

Liver
Amino acids metabolism
Iron storage
Detoxification
5 processes in digestion
INGESTION
Taking in food
DIGESTION
Breakdown of complex
food substances into smaller
soluble food substances
ABSORPTION
Digested food is absorbed
Into body cells
ASSIMILATION
Absorbed food is use to
provide energy or form
new protoplasm
EGESTION
Removal of undigested food
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
 Structure:
Amino acids
central carbon
amino group
acidic group (Carboxyl)
R group (side chain)

 variable group
 gives unique
chemical properties
to the amino acid
H
O
H
|
||
—N—
—C— C—OH
|
H
R
Deamination
H
O
H
|
||
—N— —C— C—OH
|
H
R
Amino group
Carbon residue
Ammonia (toxic)
glucose
Urea (non-toxic)
glycogen
Deamination
H
O
H
|
||
—N— —C— C—OH
|
H
R
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!
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
www.bbc.co.uk
Think about it….
Bile has a yellow-green or golden color ..
http://www.humanillnesses.com/original/Her-Kid/Jaundice.html
Detoxification
Liver in alcohol metabolism
• Liver can break down 10cm3 of alcohol in an
hour
Alcohol
Carbon 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.
2.
3.
4.
Deamination of amino acids
Iron storage
Production of bile
Detoxication
More functions of livers?
Coming soon!