160 likes | 510 Views
CHOLESTEROL. Origin. It is composed of 2 Greek words: Chole= bile. Steros= solid. It was first discovered ,in solid state as a compound in a gallstone, by a French doctor called Francois Poulletier de La Salle. Importance of Cholesterol. It is important for the formation of cell membrane:
E N D
Origin • It is composed of 2 Greek words: Chole= bile. Steros= solid. It was first discovered ,in solid state as a compound in a gallstone, by a French doctor called Francois Poulletier de La Salle
Importance of Cholesterol • It is important for the formation of cell membrane: • It regulates its fluidity. • It regulates its relative permeability to hydrophilic substances.
Importance of Cholesterol • Main component in the synthesis of steroid hormones such as oestrogen and testosterone. • It is deposit in the skin which makes our skin water proof. • Vitamin D in made from cholesterol, in skin cells stimulated by ultraviolet light. • Used for making bile.
Cholesterol story • Cholesterol is present in the diet, especially in meat, egg and dairy products. • It is absorbed in the small intestine. • The cholesterol in dairy product reduces the activity of one of the enzymes that catalyses the synthesis of cholesterol from acetyl coenzymeAin the liver. • Large quantities of saturated fats in diet cause the liver to increase the rate of the enzyme.
Transportation of cholesterol in the blood • Cholesterol is not water soluble(hydrophobic). • It is transported in blood plasma as lipoprotein.
Lipoprotein in blood Low density lipoprotein (LDL): High density lipoprotein (HDL): Protect against plaques. May even remove plaques. • Deposits as plaques on the blood vessel wall. A high ration of HDLs to LDLs can reduces the risk of cardiovascular diseases.
Risks of cholesterol • Cardiovascular diseases, like strokes and heart failure. • Gallstones in the gall bladder. • Plaques in blood vessels which causes hypertension
Factors affecting the cholesterol level You should avoid: You should do: Increase the uptake of unsaturated fats in diet. Sports and activities. • Fast food and junk food. • Excess of saturated fats in diet. • Smoking , smoking and smoking.
Made by Aya Ihab Rezeika. E-mail: ayaihab@hotmail.com References Cambridge advanced sciences- Mammalian physiology and behavior. by Mary Jones Geoff Jones Images : yahoo search