In the animal cell membrane, cholesterol exists as lipid molecules termed as steroid. Cholesterol is made up of hydrocarbon chains and the bond and size of these chains determine the flexibility of the membrane.
Cholesterol also controls the permeability of the plasma membrane by being specific to certain ions or molecules. Cholesterol plays major function in signal transduction of the cell.
The phospholipids present in the plasma membrane are also stabilized by the cholesterol.
