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Cholesterol. Soňa Lichovníková a Marek Kulíšek xclichovnikova@fch.vutbr.cz xckulisek@fch.vutbr.cz. What is it?. Cholesterol is a lipid substance , it belongs to sterols and it has quite complicated molecule (several carbon rings).
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Cholesterol Soňa Lichovníková a Marek Kulíšek xclichovnikova@fch.vutbr.cz xckulisek@fch.vutbr.cz
What is it? • Cholesterol is a lipid substance, it belongs to sterols and it has quite complicated molecule (several carbon rings). • It is a basic unit of cell-walls (membranes), participates in forming of sex hormones, hormones of adrenal gland and bile acids. • Cholesterol generates vitamin D, it is important in structure of nerve cells
How does it look like? • 4 carbon rings with a side chain - has 8 carbons • Belongs to steroids • Subgroup of sterols (due to OH group) • Lipid group
lipids - heterogenous material group, characteristic qualities: • Insolubility in water • Solubility in organic solvents • Occcurs in all body cells, mostly in nerve tissue • Also in animal fats, not in vegetable fats
Metabolism of cholesterol synthesis • about 1g/day originates by synthesis • about 0,3g/day extracted from food • Cholesterol is synthesized in : • liver, small intestine, adrenal cortex, skin, aorta • first level of metabolic pathway is acetyl-COA. Than follows more than 20 reactions
Metabolism of cholesterolsecretion • Cholesterol is secreted in 2 main ways: • Conversion on bile acids • Excretions of neutral sterols by stool • Synthesis of steroid hormone from cholesterol and elimination of their degradation products by urine.
In what food it is? • Product of animal metabolism meat brain egg yolk liver • It is risky to use technology which leads to heating up cholesterol with air (desiccation of milk and eggs, rendering of butter and lard – žluknutí – butter and lard turning rancid)
Where can it be found in body? • free, or in form of cholesterol esters with fatty acids • Their transport is allowed in blood only in form of specific elements - lipoproteins, in which fats are bound on proteins transmiters in combination with tryglicerides.
Types of lipoproteins • Lipoproteins with high density (HDL) - less cholesterol than LDL and more amount of proteins. • Lipoproteins with low density (LDL) – risky for organism, transmits much of cholesterol in blood and it more often inlay in vascular walls and it makes them thinner. • Lipoproteins with very low density (VLDL) – aren´t so important like LDL and HDL, contains quite small amount of cholesterol.
Occurrence in world? • Low levels of HDL - smokers and overweight persons. • High levels of HDL – in some long-lived families. • High levels of HDL – persons with good physical shape, also moderate periodic consummation of alcohol can increase HDL. • higher occurrence of ischemic heart disease in USA and in Europe. (Czech republic - third).
Diseases which are caused due to cholesterol • cholesterol stores into vessels in the form of it’s compounds – necking of vessels, ISCH, ateriosclerosis
Amount of cholesterol - optimal 300 mg per day and less. Genetics and it´s role (look at our parents) • Synthesis and degradation of cholesterol is genetically predicted. • But the main influence have also outer conditions, mainly the food we eat.
How to reduce cholesterol? • Lower also income of sugars and maily alcohol • medicaments: statines, fibrates and their combination
Curiosities • For the first time cholesterol was isolated in 18th century from bile stones. • Another research found that this steroid alcohol occurs in all cells of human body.
Curiosities • Cholesterol under microscope
References • http://www.lekarna.cz/detail.php?id=122 • http://www.brnacek.cz/poradna/zivot/2.htm • http://www.faf.cuni.cz/Gerontology/nutrition/agedependence/Agedependence.asp • http://www.fitnet.cz/vyziva/ZSP02.html • http://www1.lf1.cuni.cz/~zfisar/bhap/6dalsi.htm#6_2 • http://www.pacienti.cz/hcy-PS04.htm • http://www.referaty.sk/index.php?referat=3355