Lipid Transport Flashcards
(18 cards)
Types of lipids?
Triglycerides (mono - and Di-), fatty acids, cholesterol, phospholipids, vitamins A, D, E and K
-Cholesterol linked to fatty acids → cholesterol esters
Typical total cholesterol conc. Range?
< 5.0 mmol/L
How are lipids transported in blood?
Bound to carriers to travel in blood
- ~2% (mostly fatty acids) bound to albumin → limited capacity
- ~98% lipids carried as lipoprotein particles
How are phospholipids classified and what are the 2 classifications?
Classified according to head group
→Choline= phosphotidylcholine
→ inositol = phospnotidylinositol (important signalling molecule)
Difference b/w liposome and micelle?
Liposomes have a different environment in centre, micelles are monolayers and form basis of lipoprotein particles
Where is cholesterol synthesised? How is it transported around body?
Liver and transported as cholesterol esters
Role of cholesterol in plasma membranes?
Modulates fluidity
What molecules is cholesterol a precursor of?
- Steroid hormones
→ cortisol
→Testosterone
→ Oestrogen
→ aldosterone (produced by adrenal cortex) - bile salts
Structure of lipoproteins?
Peripheral, integral apolipoproteins + phospholipid monolayer + little cholesterol + cargo
What consists of the cargo?
Tags, cholesterol esters, lipid soluble vitamins
What are the 5 classes of lipoproteins?
Chylomicrons, VLDL, LDL, IDL, HDL
Which classes are the main carriers of fat?
Chylomicrons, VLDL
Which classes are the main carriers of cholesterol esters?
LDL, IDL, HDL
How can the classes be separated?
Electrophoresis, flotation ultracentrifugation
What are the 6 major classes of apolipoproteins?
A, B, C, D, E, H
Which lipoprotein classes belong to ApoB?
Chylomicrons,VLDL,IDL,LDL
Which lipoprotein class belongs to ApoAI?
HDL
What are the 2 roles of apolipoproteins?
→ structural (packages water insoluble lipids)
→ cofactor for enzymes
→ ligands for cell surface receptors
