LDL (low density lipoproteins)

low density lipoproteins are "particles" found in blood that contain cholesterol. Structurally, they are in the shape of a sphere with the outer boundry being composed of a single layer of phospholipid. In the core of the sphere is found esterified cholesterol. Inserted into the phospholipid shell are proteins called apoB proteins.

HDL (High density lipoproteins)

High density lipoproteins have a composition similar to that of low density lipoproteins with the exception that apoA protein is inserted into the phospholipid shell in high density lipoproteins.


cholesterol esterified to fatty acid


receptor mediated endocytosis