Cholesterol is a structural component of the cell membranes of animals. Because of cholesterol that provides cell membrane structural integrity and fluidity, animal cells need not to have cell walls such as that in bacterial and plant cells.Cholesterol reduces permeability of lipid membranes. ... Cholesterol plays has a role in membrane fluidity but it's most important function is in reducing the permeability of the cell membrane. Cholesterol helps to restrict the passage of molecules by increasing the packing of phospholipids.
