CHOLESTEROL

1. Other name is parental steroid.
2. It is present all over the body but absent in cerebrospinal fluid.
3. Cholesterol is found exclusively in animal food.
4. It has also been reported to occur in Potato.
5. The major part of body cholesterol is synthesized in liver and adrenal cortex.
6. Other organs taking part in synthesis of cholesterol are skin, intestine, kidneys, ovaries and testes.
7. Normal cholesterol concentration of blood is 140 - 250 mg/100 ml.
8. It also forms component of low density lipoproteins (LDL or b -lipoprotein, 10 - 25%) and high density lipoproteins (HDL or a -proteins, 20%).
9. Concentration of LDL and VLDL is found to increase in atherosclerosis and coronary thrombosis.
10. Cholesterol is component of cell membranes in animals and wall-less bacteria called mycoplasma.
11. It helps in formation of bile salts.
12. Cholesterol prevents premature breakdown of erythrocytes.
13. Cholesterol transports fat to liver for metabolism.
14. It produces sex hormones - progesterone, estrogen (female sex hormones) and testosterone (male sex hormone).
15. Moulting hormone ecdysone is formed from cholesterol in insects.
16. On combination with a saturated fatty acid, cholesterol forms yellowish plaques in the walls of large and medium sized arteries. The walls become thick fibrotic and calcified. The phenomenon is called atherosclerosis. It narrows lumen of arteries resulting in reduced flow of blood.
17. Birth control tablets possess steroid hormone progesterone.