Lipoproteins
Start with the big picture
Lipoproteins are spherical transport complexes with a core containing triacylglycerols and cholesteryl esters, surrounded by a surface monolayer that includes phospholipids, free cholesterol, and apolipoproteins. As density rises from chylomicrons through VLDL, IDL, and LDL to HDL, lipid content falls and protein content increases. The particles differ in their primary cargo: chylomicrons carry dietary TAG, VLDL carries hepatic TAG, LDL carries cholesteryl esters, and HDL carries cholesterol from tissues. Apolipoproteins contribute structure and functional specificity, including roles as enzyme cofactors and receptor ligands. These features help explain how lipoproteins participate in exogenous and endogenous transport, reverse cholesterol transport, and clinically relevant lipid patterns.
What you'll learn
- Describe the core–surface organization of a lipoprotein.
- Order major lipoprotein classes by density and relate density to lipid and protein content.
- Identify the primary cargo carried by chylomicrons, VLDL, LDL, and HDL.
- Explain structural and functional roles of apolipoproteins.
- Distinguish the exogenous, endogenous, and reverse cholesterol transport pathways.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
