胆固醇高密度脂蛋白（HDL） 3D模型

Cholesterol is an essential structural component of animal cell walls and are transported in the blood flow around the body within a range of Lipoprotein structures. This model depicts a High Density Lipoprotein, often referred to as 'Good' cholesterol since HDLs absorb cholesterol (pale green) and return it to the liver. This is in contrast to larger Low Density Lipoproteins ('Bad' cholesterol), which can lead to build-up of fatty deposits inside the blood vessesl. Included are representations of the protein surface and structure (shown as ribbons along the polypeptide backbone), a polygon mesh of the lipid-lipid bilayer that makes up the outer surface and models of individual lipid and cholesterol molecules that are instanced/duplicated to create the surface. The model is scaled by factor of ten million (actual size of HDL = 11nm diameter, 3d model = 0.11 m diameter)