Cholesterol is a sterol with the molecular formula C27H45OH. It possesses a cyclopentanoperhydrophenanthrene nucleus and has functional groups including an -OH group at C3 and an unsaturated double bond between C5&C6. Cholesterol is a major component of cell membranes, especially in nerve and brain tissue. It is also a precursor molecule used to synthesize vitamin D, estrogen, and bile acids. Cholesterol is mainly synthesized by the liver and is essential for cell membrane structure and producing other important molecules, though high dietary intake can increase risk of heart disease.

1. Sterol

2. Structure of Cholesterol

3. • Molecular formula: C27H45OH
• Possesses cyclopentanoperhydrophenanthrene
nucleus
• Has an –OH group at C3
• Unsaturated double bond between C5 & C6
• Two –CH3 groups at C10 & C13

4. Function of cholesterol
• Major component of cell membranes
(especially abundant in nerve and brain tissue)
• Precursor molecule: Example - Vitamin D and
estrogen are synthesized from cholesterol
• Important in the synthesis of bile acids

5. Cholesterol
• Cholesterol is a derived lipid. Its widely distributed
as sterols in animals and humans
• Its an essential component of cell membrane
• Vit. D, hormones and bile acids are synthesised from
cholesterol.
• Bile acids are essential for normal digestion and
absorption of fats and fat-soluble vitamins.
• Most of the cholesterol is synthesised by the liver
• An increase in dietary intake of cholesterol, increases
its synthesis in the body as well which leads to
coronary heart diseases.
• Unsaturated fats reduce the level of cholesterol in
blood.

6. Sterols: Cholesterol
• Functions
– Component of cell membranes
– Precursor to other substances
• Sterol hormones
• Vitamin D
• Bile acids
• Synthesis
– Made mainly in the liver
• Food sources
– Found only in animal foods