A sterol or a modified steroid that is synthesized by animal cells to become an essential component of animal cell membranes
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 in animal cell membranes also enables the animal cells to change shape and therefore are rather flexible than plant cells (which are less flexible in shape due to the presence of the cell wall).
Cholesterol is found in animal tissues, especially in animal fats and oils, bile, blood, brain tissue, milk, egg yolk, myelin sheaths of nerve fibers, liver, kidneys, and adrenal glands.
In humans, routine checkup to determine the level of cholesterol is important since an abnormally high or low cholesterol levels in the blood may implicate pathological conditions. For instance, increased cholesterol level may be associated with cardiovascular diseases and gallstone formations. Low cholesterol level, in contrast, is linked to chronic kidney disease and depression.
Word origin: Greek chole– (bile) + stereos (solid) + –ol
IUPAC name: (3β)-cholest-5-en-3-ol
Chemical formula: C27H46O