1st Book Flashcards
What is the core composition of chylomicrons?
Core of TAG and cholesterol ester surrounded by a layer of phospholipids and cholesterol
What are the two types of proteins associated with chylomicrons?
- Integral part (cannot be removed): apo A and B
- Peripheral part (can be removed): apo E and apo D
Where is chylomicron biosynthesis primarily located?
Intestinal mucosa
When does chylomicron biosynthesis occur?
After meal
What is the lipid composition of chylomicrons?
- Amount of lipids: 98%
- Amount of proteins: 2%
What is the main lipid type found in chylomicrons?
Dietary triacylglycerol
What is the primary function of chylomicrons?
Carry dietary lipids from intestinal mucosa to peripheral tissues
How are chylomicrons formed?
Formed in the intestinal mucosa after meal, cannot pass through portal circulation due to large size
How do chylomicrons enter the systemic circulation?
Pass through lymphatics via thoracic duct to superior vena cava and then to heart
What happens to chylomicrons in plasma?
Nascent chylomicrons take apo C2 and apo E from HDL and become mature chylomicrons
What is the role of lipoprotein lipase in chylomicron metabolism?
Hydrolyses triacylglycerol of chylomicrons into glycerol and fatty acids, clearing post-prandial turbidity
What happens to apo C2 after chylomicron metabolism?
Returns to HDL, causing chylomicrons to shrink and become chylomicron remnants
How are chylomicron remnants processed in the body?
Removed by the liver receptor which recognizes Apo B 48 and Apo E
What results from a deficiency of lipoprotein lipase or Apo C2?
Accumulation of lipoproteins rich in triacylglycerol (Type I hyperlipoproteinaemia)
Fill in the blank: Chylomicrons are formed in the _______.
Intestinal mucosa
True or False: Chylomicrons can pass through the portal circulation.
False
