HW 1 5 Steroids Lipids and Cardiovascular Disease

HW 1 -5: Steroids, Lipids and Cardiovascular Disease

Steroids include cholesterol and certain hormones • Steroids are lipids with a carbon skeleton consisting of four fused carbon rings. • Different steroids are created by varying functional groups attached to the rings. Male Sex Hormone Cholesterol Copyright © 2002 Pearson Education, Inc. , publishing as Benjamin Cummings

CHOLESTEROL IS AN ESSENTIAL -COMPONENT OF CELL MEMBRANES -PRECURSOR FOR SYNTHESIS: STERIODS, BILE ACIDS TO AID IN DIGESTION OF FATS, VITAMIN D Cholesterol (c) Cholesterol within the animal cell membrane Cholesterol animation

Heart Attack and Strokes can be caused by blockage of arteries • Heart Attack - #1 cause of death in US; blockage of coronary arteries by plaque supplying blood to heart • Stroke #4 cause of death in US; blockage of arteries carrying blood to brain or rupture of blood vessels in the brain that prevents blood flow. Thrombosis and Embolism

Narrowing of arteries due to buildup of plague increases the risk of heart attack and stroke Mechanism of thrombosis

Lipids including cholesterol are carried in blood by lipoprotein particles HIGH LEVELS OF LOW DENSITY CHOLESTEROL (LDL) INCREASE THE RISK OF HEART ATTACK AND STROKES BY INCREASING CHOLESTEROL DEPOSITED IN PLAQUES; HDL REMOVES CHOLESTEROL FROM PLAQUES

IB Bio Exam • Trans fatty acids are not abundant in nature • Created as side product of hydrogenation of unsaturated cis fatty acids during food production. • Trans Fatty acids in diet ↑ Low-Density Lipid cholesterol and ↓ High Density Lipid cholesterol concentrations in blood which increases heart attack and stroke risk. Also increase of inflammation. Exact Mechanism is unknown.

Mayo Clinic

Figure 5. 11 Examples of saturated and unsaturated fats and fatty acids Video link Solids at RT Note: cis-double bonds (bent shape) are much more common in nature than trans Liquids at RT

IB BIO EXAM