Cholesterol (from the Ancient Greek chole- (bile) and stereos (solid), followed by the chemical suffix -ol for an alcohol) is an organic molecule. It is a sterol (or modified steroid), a type of lipid molecule, and is biosynthesized by all animal cells, because it is an essential structural component of all animal cell membranes and is essential to maintain both membrane structural integrity and fluidity.[citation needed] Cholesterol allows animal cells to function without a cell wall (which in other species protects membrane integrity and cell viability); this allows animal cells to change shape rapidly.source:wikipedia
