Explain how the structure of cholesterol enables it to perform structural and functional roles within membranes

Cell membrane is comprised of phospholipids (its major component ) which can create lipid bilayers because of their  water attracting characteristics.  Another lipid inside the cell membrane is cholesterol, which makes the cell membrane more fluid. Cholesterol is a waxy fat-like substance found in all cells of the body. 
When you have a high cholesterol, it can create a plaque in your arteries thus, develop a high risk of heart disease. People who have high cholesterol has a greater possibility to acquire coronary heart diseases.