<< Phospholipids | Cholesterol | Semi-permeability and Osmosis >>

Cholesterol is a major component of cell membranes and serves many other functions as well. Cholesterol helps to 'pack' phospholipids in the membranes, thus giving more rigidity to the membranes. In colder conditions cholesterol also serves to keep the fluidity in the cell membrane, by keeping space in between the phospholipids. Also cholesterol serves diverse functions such as: it is converted to vitamin D (if irradiated with Ultra Violet light, modified to form steroid hormones, and is modified to bile acids to digest fats.