What are the 2 mechanisms human bodies obtain cholesterol and fatty acids?
1. Biosynthesis (de novo): liver
2. Dietary: absorption by intestine
What causes blood serum to be cloudy?
Lipoproteins (chylomicrons) reflecting light
What is the good cholesterol?
HDL
What is the bad cholesterol?
LDL
What does the lipid panel measure?
Total Cholesterol Level
Triglyceride Level
HDL Cholesterol Level
LDL Cholesterol Level
What is the #1 lipid in the body or diet?
Triacylglycerols
How can cholesterol be returned to the intestine?
Can be converted to bile and returned via the gall bladder
Why do we need to make lipoproteins instead of creating triacylglycerols?
Triacylglycerols are extremely greasy and are insoluble in blood serum
Where are lipoprotein lipases found?
Endothelial walls of fat tissues
Where are HDL's formed?
In the blood.
Liver and intestine release protein A1 into the blood and that's where it gets formed
Why are HDL's considered good?
They grab onto cholesterol and return it to the liver
Why are LDL's considered bad?
They are small and dense enough to go into the endothelial blood vessel surfaces and accumulate in the tunica intima. The buildup of LDL's is the first step in development of atherosclerotic plaques
What is the job of HDL?
To accumulate cholesterol
What does LCAT (Lecithin-cholesterol acyl transferase) do?
Takes 1 fatty acid linked to glycerol and transfers it to a cholesterol
Catalyzes reaction that transfers fatty acid from phosphatidylcholine to cholesterol
What does cholesterylester transfer protein do?
Transfers cholesterylesters from HDL's to VLDL's
If there is a low HDL level, will there be high or low levels of triacylglycerols?
High
What is the relationship between HDL and triacylglycerols?