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Fats

one important of macronutrient . each one gm of fat yield 9 kcal of

energy . importance of fat : 1-source of energy & storage . 2-essential nutrient supply . 3-food satiety [ feeling of taste ,& add

flavor to food , slow gastric emptying .

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Function of Fat :

1-energy production . 2-thermal insulation . 3-vital organ protection . 4-nerve impulse transmission . 5-enter in cell membrane structure & help in

transportation of nutrient cross the cell membrane .

6-enter in cell metabolism { lipo protein carry fat in the blood to all cells }.

7-essential precursor substance{ fatty acid & cholesterol }.

N B : too much of fat store in adipose tissue lead to increase body WT hypertension ,heart disease ,diabetes mellitus .

*physical characteristic of fat : greasy in touch ,insoluble in water .

*types of fat : 1- saturated fat : comes from animal origin ,fatty

acid saturated with hydrogen . 2- monosaturated fat : comes from plant origin as

olive oil ,fatty acid saturated with one hydrogen ion .

3- poly saturated fat : fatty acid is saturated with two or more of hydrogen ion ,comes from plant source as coconut oil, palm oil .

*essential fatty acid : the body cant manufacture it &

therefore must obtain it from the diet . -function : @ membrane structure { strength the

cell membrane }. @cholesterol transport to blood . @has role in blood clotting prolonged of

clotting time @ local hormone like effect

{ prostaglandin ,prostacycline thromboxane ,& leukotriens

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Prostaglandins :

1stly discovered in the semen which comes from prostatic gland .

Has role in smooth mulched tone & platelet aggregation .

Derived from fatty acid Hormone like action ,regulation of

gastric acid secretion. Has role in inflammatory process & body

temp. control . Lower of Bp .

*Triglycerides

Three fatty acid chains attached with glycerol ,[ monoglycerids ,diglycerids ,triglycerides ].

saturated fatty acid comes from animal source as milk , meat ,eggs .

unsaturated fat comes from plant source as vegetable oils .

visible & hidden food fat : visible butter, margarine ,oil salad

dressing ,bacon & cream . hidden fat : egg yolk is fat , white is pure

protein , also nuts seeds , olives ,avocadoes

*cholesterol :

Run in blood stream , consider vital structure in human metabolism , origin from steroid .

essential in formation of bile . enter in enzymatic digestion of fat . found in large amount in the brain

&nerve tissue . essential component of cell membrane . cholesterol has role in cardio vascular

disease { atherosclerosis }.

NB: Lipoprotein is a mixture of lipid &

protein . -HDL: high density lipoprotein . -LDL: low density lipo protein . * digestion of fat: -in the mouth fat break down into small

particles by chewing & mastication . -in the stomach mechanical mixing of

fat with gastric secretion .

- in the small intestine , bile secretion & pancreatic enzyme , with small intestine secretion digest fat .

- because fat is not water soluble unite with protein to form lipo protein go to lymphatic system for absorption .

- metabolism : burn out of fat to produce energy .

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Thanks for Your Attention!

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