Cholesterol is a lipid belonging to the sterol family, found specifically in animals.
Roles of cholesterol
Cholesterol is a hydrophobic molecule which is insoluble in water. It is therefore transported in blood notably by proteins
- low density lipoproteins (LDL) which carry cholesterol to the cells and are responsible for cholesterol deposition in the arteries: this is bad cholesterol .
- The high density lipoproteins (HDL) carry cholesterol towards the liver where it is degraded and is the good cholesterol.
Composition of cholesterol
Cholesterol is composed of a steroid nucleus (four carbon rings A, B, C and D, the first three with 6 carbon atoms and the D ring with 5 carbon atoms for the D cycle). It has an alcohol group (-OH) on the third carbon atom, on which a fatty acid may be esterified (cholesterol ester).
Cholesterol is the substance found in animal fats, egg yolk, and in the human body.
Cholesterol is a lipid belong to the sterol family. © DR