Cholesterol Flashcards
What are the three primary sources of fats?
- The diet
- De novo biosynthesis (liver)
- Storage depots in adipose
What breaks down dietary fats?
Lipases
What are needed to solubilize dietary fats?
Bile acids
What does a lack of bile acids result in?
Steatorrhea (Fatty stool) - this is because majority of fat passes throuhg the gut undigested and unabsorbed
What produced bile salts?
Liver
What do bile salts do in digestion?
They emulsify fats in the intestine and aid the digestion of fat soluble vitamins (A, D, E and K)
What is Orlistat?
A potent inhibitor of gastric and pancreatic lipases
What is the main side effect of Orlisats?
Steatorrhea
what do lipoproteins do?
Transport lipids in the plasma
Where are chylomicrons produced and what is their role?
Intestine - dietary fat transport
Where are digested dietary products absorbed?
By the enterocytes that line the brush border of the small intestine
Where do chylomicrons acquire apoproteins from?
From HDL following release into the blood stream
How do chylomicrons enter into the blood stream?
Travel from the lacteals of the intestine into the thoracic duct and into the left subclavian vein from which they enter into the blood stream
What is the primary role of cholesterol in the body?
Maintenance of cell membrane integrity - can increase or decrease the stiffness depending on the temperature and nature of the membrane
How are all the physiological requirements for cholesterol met?
They are supplied by the liver thorugh the de novo synthesis of cholesterol from Acetyl CoA
What is the first step in cholesterol biuosynthesis?
Acetyl CoA + Acetyl CoA = Acetoacetyl CoA
Condensation of 2 Acetyl-CoA molecules to form Acetoacetyl CoA.
What is the second step of cholesterol biosynthesis?
Condensation of another Acetyl-CoA molecule to form HMG-CoA - using HMG-CoA Synthetase