Exam 2 Study Guide:Lipids:Functions of lipidsNature’s way of condensing energy storesAlso insulates and protects organsSource of calories (9Kcal/gram)Provides flavor and tenderness of foodSlows stomach emptying, more satiating Source of essential fatty acidsTypes of LipidsPhospholipids- cell membranesSterols- hormonesTriglycerides- predominant in food (95%)PhospholipidsGlycerol + 2 fatty acids + phosphorusPhosphorus part makes this soluble in waterFatty acid part makes it soluble in fat Can serve as an emulsifier SterolsLarge molecules consisting of interconnected rings of carbon atoms with side chains of carbon, hydrogen and oxygen attachedCholesterolFound in all animal cell membranes NonessentialForms plaques that cause athrosclerosisServes as raw material for: bile, vitamin D, steroid hormonesTriglyceridesMain form of fat in foodGlycerol backbone and 3 fatty acidsClassified by length of carbon atoms, the location of the double bonds, and the organization of hydrogen around the double bondsSaturated Fatty Acids:Maximum number of hydrogen atomsUnsaturated Fatty Acids:Less then maximum hydrogen atomsMonounsaturated: 1 double bondPolyunsaturated: 2 or more double bonds***Found in soft solids or liquidsTrans Fatty Acids: Fatty acids with unusual shapesPolyunsaturated oils that are hydrogenated+ = control consistency and oxidation of fats- = increase LDL***Found in margarines, shortenings and baked goodsEssential Fatty Acids:Made in limited amounts in the bodyAbundant in fish oilsLower blood pressurePrevent blood clot formationProtect against irregular heartbeatsMay reduce inflammationEssential for normal infant growth/developmentMay support immune systemMay inhibit cancersOmega 3 Fatty Acids:Linolenic AcidFound in tuna, salmon, herring, flax see, canola/soybean oils, almonds, walnuts, spinach, mustard greensReduce inflammation, blood clotting and tumor growthOmega 6 Fatty Acids:Linoleic AcidFound in grains, fats and oilsCause inflammation, blood clotting and tumor growth*Eicosanoids- hormone like compounds that are made from EEFAs and act through receptors on tissues to regulate many body responses*Digestion Depends on:Pre-duodenal Lipase (gastric)Pancreatic lipaseBile acids for emulsificationLipase breaks down triglycerides into free fatty acids and monoglyceridesAbsorption:Short chain fatty acidsPortal vein (blood to liver)Monoglycerides and longer fatty acidsGet repackaged as triglycerides for transport in chylomicronsEnter lymph then the blood streamTransport as Lipoproteins:Chylomicrons- from the intestine to the bodyOther produced in the liverVLDLs (very low density lipoproteins) BADLDLs (low density lipoproteins) BADBoth triglycerides and cholesterol to the bodyHDLS (High density lipoproteins) GOODScavengers of cholesterol, brings it back to the liverTotal cholesterolLess than 200 is desirable200-239 is borderline bad240 and above is BADProteins and Amino Acids:What do proteins do?Build tissue, growth or replacements of parts, enzymes, hormones, antibodies, fluid electrolyte balance, acid-base balance, energy, transportation, blood clotting, structural componentsHow much do we need?DRI recommendation is dependent on size and stage of growthDRI recommendation of .8 grams per kg of body weightMinimum is 10% of total caloriesAthletes may need slightly more (1 gram per kg)Classification of amino acidsEssential (9)- histidine, isoleucine, leucine, lysine, methionine, phenylaline, threonine, tryptophan and valineNonessential (11)Protein DenaturationHeat, acid, alcohol, base, saltsVitaminsOrganic compounds contain carbon many different structures form simple to complexNon-caloricEssential lack of vitamins leads to deficiency syndromes, can not be synthesized in the body (with exceptions)Needed in small amounts ClassificationFat-solubleVitamins A,D,E and KAbsorbed like dietary fat, requires bileCarried in the blood using protein carriersCan be stored in body fat, mainly liverGenerally have greater body stores then water-solubleHigh likelihood of toxicityWater-solubleThiamin, riboflavin, niacin, pantothenic Acid, B6, CGenerally have lower body stores then fat-soluble vitaminsUsually excreted in urineLow in toxicityVitamin AFunctions:Eyesight, gene regulation, cell differentiation, immune function, growth of bone and teeth ToxicityFrom fortified foods Concern of pregnant women, children and adolescentsFrom AccutaneBeta CaroteneVitamin A precursor found in plants water soluble, low in toxicity, found in bright orange fruits and vegetables and leafy greensMany carotenoids but beta carotene is the most abundantAntioxidantsPrevents free radicals from causing damage to body structures such as cell membranes and DNAVitamin C/E, zinc, selenium, copper and phytochemicalsFree Radical DamageMolecules often oxygen with unpaired electrons that cause damage to the body’s structuresSources: mitochondria, immune system, pollutants, cigarette smokeCell membranes and lipids causing cells lysisInactivation and degradation of proteins and enzymesDamage to DNA Chain rxn road block =antioxidantsDiseases associated: heart, cancer, aging, cataractsSourcesFortified milk, carrots, beef liver, sweet potatoes, apricotsVitamin DFunctionsRegulated blood calcium and phosphorus levelsHelps to maintain bone integrityStimulates maturation of cells including immune cellsActs on genes affecting how cells grow and multiply diseases (cancer, multiple sclerosis) Highly toxicDeficiency Rickets:Poor bone mineralizationBody weight causes legs to bowSources: Fortified milk, salmon, shrimp, liver, SUNLIGHTVitamin EFunctionsProtects cell membranesRegulates oxidation reactionsAntioxidant (lungs, RBC, immune cells, brain cells)SourcesCanola oil, safflower oil, mayonnaise, wheat germ, sunflower seedsVitamin KFunctionsSynthesis of blood clottingSynthesis of proteins important to bone mineralizationMade by intestinal bacteriaNewborns given a dose of VK at birthAntibiotic overdose can lead to VK deficiencySources Cabbage, spinach, soybeans, canola oil, salad greensVitamin CFunctionsAssists in enzyme involved in the formation and maintenance ofcollagen, wound healing acts as an antioxidant especially protecting the immune system cells from free radical generation**smokers should take more to counter act free radicalsSourcesSweet potatoes, strawberries, broccoli, brussel sproutsFolic Acid (Folate)FunctionsPart of a coenzyme needed for new cell synthesisSourcesAsparagus, avocado, beets, legumes,
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