Metabolism of Lipids/Lipoproteins Flashcards
What are the four major pathways involved in Lipoprotein Metabolism?
Lipid Absorption
Exogenous
Endogenous
Reverse Cholesterol
What are the Processes that are used to transport dietary and hepatic derived lipids AND which Apolipoprotein does it involve?
Exogenous
Endogenous
Apo B
Why are Peripheral cells prone to accumulating Cholesterol?
They make their own Cholesterol, but lack the enzymes to break it down
What is another name for the Liquid Absorption Pathway?
Intracellular-Cholesterol Transport
Where does the processing of Dietary Lipids occur?
Small Intestine
The Gallbladder is responsible for what?
Storing Bile Salts made by the Liver
What must we do to Lipids that have entered into the Duodenum?
Emulsify fat with Bile Salts to produce tiny droplets
What is the role of Colipase?
Help Pancreatic Lipases break down Triglycerides
What is produced from Intracellular Cholesterol Transport?
Chylomicrons
What is the role of the Exogenous Pathway?
Transport Dietary Lipids from Intestine to the Liver and cells
Hydrolysis of Triglycerides is cause of what?
The production of Fatty Acids and Glycerol
Cells take these up to use as energy
The body is in need of energy and is low in Carbs. What method can we use to get energy?
Hormone Sensitive Lipase releases Fatty Acids and Triglycerides stored in fat
What role does HDL play in the Exogenous Pathway?
Accepts Lipids and Apolipoproteins during the Lipolysis of Chylomicrons
Causes Chylomicron to be converted into a Chylomicron Remnant
Cholesterol can be converted into Bile Acids in the Liver. What can be done with the Bile Acids?
Can be reabsorbed by the Small Intestine (50%)
Reused by the liver for Bile production
What is the role of the Endogenous Pathway?
Transfer Hepatic Triglycerides to Cells
Which Apolipoprotein is important in the Endogenous pathway?
Apo B-100
The Lipoprotein IDL is specific to which pathway?
Endogenous
What is the role of IDL in the Endogenous Pathway?
Travel back to the liver to either be absorbed or converted into LDL (50%)
LDL is taken efficiently by LDL receptors making it what?
The major Lipoprotein responsible for delivering Exogenous Cholesterol
What is the role of the Reverse Cholesterol Pathway?
Remove excess Chol. and return it to the Liver
What allows Cholesterol to be actively pumped out?
ATP Binding Cassette Transporter G1 (ABCG1)
How are disc shaped HDL formed?
ABCG1 binding to Apo A-1
Cholesteryl Esters are trapped in the core of an HDL until what removes them?
Lecithin Cholesterol Acyltransferase (LCAT)
How does the Liver remove Cholesteryl Esters from the Spherical HDL?
Scavenger Receptor B-1 (SR-B1)
