Study guide for Chapter 6 Unit 20 and 23 Chapter 14 Lipids organic molecule that is relatively insoluble in water and soluble in organic solvents source of energy and needed for optimal health ex Oils and fats o Major lipids Phospholipid a type of lipid composed of a glycerol bonded to two fatty acids and a polar head Sterol a type of lipid with a distinctive multi ring structure a common example is cholesterol Sterol ester a chemical compound consisting of a sterol molecule bonded to a fatty acid via an ester linkage Cholesterol a sterol found in animal food and made in the body required for bile acid and steroid hormone synthesis o Cholesteryl ester a sterol ester made of a cholesterol molecule bonded to a fatty acid via an ester linkage Triglycerides Fatty acids Fat soluble vitamins Fatty acids a type of lipid consisting of a chain of carbons with methyl CH3 group on one end and a carboxylic acid group COOH on the other o Structure made entirely of carbon hydrogen and oxygen atoms A chain of carbons atoms forms the backbone of each fatty acid One end of this carbon chain is the alpha end and the other end is called the omega end Most fatty acids do not exist in their free unbound form Instead they are components of larger molecules such as triglycerides and phospholipids Fatty acids are bound to cholesterol forming cholesteryl esters Alpha end the first letter in the Greek alphabet The end of a fatty acid which consists of a carboxylic acid group Omega end the final letter in the Greek alphabet The end of a fatty acid which consist of a methyl group Saturated fatty acids to fill or satisfy a fatty acid that contains only carbon carbon single bonds in it backbone Unsaturated fatty acids a fatty acid that contains at least one carbon carbon double bond in its backbone Polyunsaturated fatty acids a fatty acid that contains more than one carbon carbon double bond in it backbone Monounsaturated fatty acids a fatty acid that contains one carbon carbon double bond in its backbone Chain length the number of carbons in a fatty acid s backbone o Short chain fatty acid a fatty acid having 8 carbon atoms in its backbone o Medium chain fatty acid a fatty acid having 8 12 carbon atoms in its backbone o Long chain fatty acid a fatty acid having 12 carbon atoms in its backbone Arrangement of hydrogens o Cis double bond a carbon carbon double bond in which the hydrogen atoms are positioned on the same side of the double bond o Trans double bond a carbon carbon double bond in which the hydrogen atoms are positioned on opposite sides of the double bond Difference between cis is that the hydrogen s are on the same side of the fatty backbone whereas trans hydrogen s are on opposite sides of the fatty acid backbone o Trans fatty acids a fatty acid containing at least one trans double bond Omega 3 fatty acids a fatty acid in which the first double bond is located between the third and Omega 6 fatty acids a fatty acid in which the first double bond is located between the sixth and fourth carbons from the methyl or omega end seventh carbons from the methyl or omega end Essential fatty acids o Linoleic acid an essential omega 6 fatty acid with 18 carbons and 2 double bonds o Linolenic acid an essential omega 3 fatty acid with 18 carbons and 3 double bonds Essential fatty acid deficiency these are rare because of the almost endless supply of linoleic and linolenic acids stored in adipose tissue Primary generally occurs only in hospitalized patients receiving poor nutritional care Secondary can occur with diseases that disrupt lipid absorptions or utilization such as cystic fibrosis Within 2 4 weeks individuals will develop irritated and flaky skin gastrointestinal problems and impaired immune functions Triglyceride a lipid composed of a glycerol molecule bonded to three fatty acids o Lipolysis the breakdown of triglycerides into fatty acids and glycerol o Lipases enzymes that cleave fatty acids from the glycerol backbone of triglycerides phospholipids and cholesteryl esters Lipoprotein lipase an enzyme that hydrolyzes the ester linkage between a fatty acid and glycerol in a triglyceride diglyceride and monoglyceride molecules as they circulate in the bloodstream Chylomicrons a lipoprotein made in the enterocyte that transports large lipids away from the small intestine in the lymph Very low density lipoprotein VLDL a lipoprotein made by the liver that contains a large amount of triglyceride its major function is to deliver fatty acids to cells Intermediate density lipoprotein IDL a lipoprotein that results from the loss of fatty acids from a VLDL many IDL are ultimately converted to LDLs o Denser form of VLDL Low density lipoprotein LDL a lipoprotein that delivers cholesterol to cells High density lipoprotein a lipoprotein made primarily by the liver that circulates in the blood to collect excess cholesterol from cells o Lowest lipid to protein ration o Reverse cholesterol transport Hormone sensitive lipase an enzyme that catalyzes the hydrolysis of ester linkage that attach fatty acids to the glycerol molecule mobilizes fatty acids stored in adipose tissue Cholesteryl esters o Adipose tissue consists of specialized cells called adipocytes which can accumulate large amounts of lipids Adipocytes a specialized cell that makes up the majority of adipose tissue Subcutaneous adipose tissue adipose tissue found directly under the skin Visceral adipose tissue adipose tissue surrounding the vital organs Lipogeneis the metabolic processes that result in fatty acid and ultimately triglyceride synthesis Cardiovascular disease a disease of the heart or vascular system o Generally caused by a slowing or complete obstruction of blood flow to the heart or other parts of the body including the brain Atherosclerosis the hardening and narrowing of blood vessels caused by buildup of fatty deposits and inflammation in the vessel walls Plaque fatty deposit that accumulates within walls of blood vessels sometimes leading to atherosclerosis Caused by a complex web of factors including genetics physical inactivity and poor diet Cardiovascular disease risk is not only influenced by total dietary lipid intake but may also be affected by specific types of dietary lipids High intakes of SFAs trans fatty acids and cholesterol can increase the risk for disease in some people whereas MUFA may have the opposite effect o Nonmodifiable risks factors Age sex generics including race prior to stroke or heart attack and having been born