Chapter 4: Fats or LipidsMacronutrient category: LipidsEther, acetone, chloroform○Fats, or lipids, are defined as substances that are insoluble in water, but soluble in organic solvents•The Lipids in our Food and our BodiesTriglycerides○Phospholipids○Sterols (Ex. cholesterol)○A wide variety of lipids influence human health:•Carbon○Hydrogen○Oxygen○Lipids are composed of the same elements that are contained in carbohydrates:•List the categories of lipidsThe major difference is that lipids contain almost twice as many hydrogen atoms than do carbohydrates, when metabolized, more energy is yielded•Discuss why lipids have more energy than carbohydratesFatty AcidsFatty acids are simply a chain of carbons linked/bonded together•Hydrophilic characteristic - attracted to waterCarboxyl group (COOH)○Hydrophobic - does not mix with waterMethyl group (CH3)○The chain has a carboxyl group on one end and a methyl group on the other•Fatty acids are not only important lipid compounds by themselves, but also as components of triglycerides and phospholipids•Discuss the structure of fatty acidsEach carbon may have up to two hydrogen's attached•Refers to the amount of hydrogen that are attached to each of the carbon in that fatty acid○Fatty acid saturation - whether a fatty acid carbon chain is occupied by all of the hydrogen atoms it can hold•Saturated fatty acid (water)○If the chain is fully occupied by hydrogen atoms, then it is a •Unsaturated fatty acid - missing a hydrogen, at least one double bond○When hydrogen atoms are missing, a double bond forms between carbons•Monounsaturated fatty acid○A fatty acid with one double bond is called•Polyunsaturated fatty acids○Two or more double bonds•Fatty Acid SaturationFatty AcidsSaturated fatty acid•Differences between saturated, monounsaturated, polysaturated fatty acidsMore solid at room temperature (ex. butter)○One double bond○Tends to stay a liquid at room temperature○Monounsaturated fatty acid•Liquid at room temperature○Polyunsaturated fatty acid•Compare the effects of saturation on the state of the fatty acid at room temperatureFatty Acids in Common Foods Nutrition Page 1Fatty Acids in Common FoodsEssential fatty acids○Must be provided in the diet○Fatty acids that cannot be made by the body, provided•Essential and Nonessential Fatty AcidsConsidered to be essential fatty acid is - Linoleic acidsOmega-6○Linolenic acidOmega-3○There are 2 families of fatty acids•IDENTIFY TWO ESSENTIAL FATTY ACIDS - REFERRING TOThe numbers 3 and 6 refer to where the double bonds are located in the fatty acids•The location of the double bonds drastically affects the function of the fatty acid•Omega-3 and Omega-6 Fatty AcidsArachadonic acid (metabolic end products, affect blood pressure, blood flow)○Omega-6 fatty acids are incorporated into cell membranes and are precursors to powerful biological compounds that can play a role in reproduction and blood flow:•Eicosapentaenoic acid (EPA) - good source is fish○Docosahexaenoic acid (DHA)○Heart diseaseLikelihood of formations of blood clotsMay reduce○Omega-3 fatty acids are also found in cell membranes and help prevent tissue inflammation•Most Americans get plenty of omega-6 fatty acids, but not enough omega-3•Discuss the effects of omega-6 and omega-3 fatty acid products in the body and on healthIdentify the two essential fatty acids and common dietary sources of each Nutrition Page 2Identify the two essential fatty acids and common dietary sources of eachTrans Fatty AcidsProcess of adding hydrogens back to unsaturated fat○Makes liquid fat a solid○Increases shelf life○Commonly found in store-bought cakes, cookies, crackers, other snack foods○Margarine and shortening other common sources○Hydrogenation•= Trans fatty acid○A fatty acid produced through addition of hydrogen atoms to double bonds of fatty acids that causes the molecule to assume anunnatural shape•Milk and meat○Only a small amount of naturally occurring trans fatty acids are found in•Define hydrogenationTrans Fatty AcidsCis - fall on the same side, maintains the bent structure○Trans - fall on opposite sides (Hydrogen lands on north and south, straightens out the fatty acid)○Cis vs. Trans fatty acids•Margarine - form of hydrogenated fatMore hydrogenated = more trans fat= Partially hydrogenated, little trans fat present○When only some unsaturated fats are converted to saturated fats via hydrogenation•Differences between cis, trans fatty acidsIncreased levels of "bad" cholesterol or lower-density lipoprotein (LDL)○May lower good or high-intensity lipoprotein○When have high low density lipoprotein and/or low amounts of HDL = increased risk for heart diseaseWhen LDL elevated and or HDL is lowCan be exaggerated by eating trans fatIncreased risk for heart disease○Dietary trans fatty acids from hydrogenation are associated with•Less than 1% of calories○The American Heart Association recommends 2 g of trans fatty acids per day or less•Trans Fatty AcidsA 3-carbon glycerol backbone○3 fatty acids are bonded to each of the carbons (glycerol backbone)○Hydrophobic - don't mix well with water○Triglyceride - a chemical structure composed of:•"eating fat" = triglycerides○Primary form of lipid fat found in food and in the body•The fatty acids in triglycerides found in the body often reflect dietary fatty acids consumed (if eating more mono/poly, triglycerides will appear the same)•TriglyceridesPhospholipids are a compound that helps your body with the task of transporting fat through watery substance•Chemically similar to triglycerides•Phospholipids Nutrition Page 33-carbon glycerol backbone○2 fatty acids bound to first two carbons○Third carbon has phosphate group bound to it○Chemically similar to triglycerides•Phosphate head is hydrophilic○Fatty acid tail is hydrophobic○Phospholipid has hydrophilic and hydrophobic quality in one unit○The presence of this phosphate group changes the physical properties of the structure•Blending of fat and water○Emulsifier will circle towards the edge, phosphate head will be exposed to the water, so fat stays dispersed○Phospholipids are uniquely suited to function as emulsifier•Cell membrane○Transport particles for fats in the bodyLipoproteins○In the body, phospholipids are important as part of •Four rings○Includes cholesterol -