Nutrition 251 Exam 2 Penn State

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Why we needs fats/lipids
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Why we needs fats/lipids
1) Insulation
2.Taste and Texture
3.Membranes of cells
4.Clotting
5.Slows gastric emptying
6.Absorbs fat-soluble vitamins
7.Sex Hormones
8.Energy (ATP)
9.Energy storage
10.Regulation of gene expression
The class of nutrients known as lipids includes:
triglycerides (fats and oils), phospholipids, and sterols.
Fatty acids are organic compounds composed of
a carbon chain with hydrogen attached
Fatty acids have an ______ group at one end and a _______ group at the other end.
acid, methyl
Carbon lengths of _____to_____ are called long chain fatty acids. Common in:
12-24, meats, fish and vegetable oils
Medium chains (6-10 carbons) and short chains (<6 carbons) occur in small amounts in foods such as
dairy products
In a saturated fatty acid, all carbon atoms make four bonds with neighboring atoms, therefore there are only single bonds. These are generally_______ at room temperature.
solid
A monounsaturated fatty acid has one _______ bond in its structure. Generally more _______ at room temperature.
double, liquid
A polyunsaturated fatty acid has ______ double bonds in its structure. Generally more ___________ at room temperature.
two or more, liquid
The presence or absence of __________ and the ______ of them creates different physical and functional characteristics
of double bonds, location
composed of a 3-carbon glycerol backbone with three fatty acids extending out from each of the carbons of glycerolA triglycerideA triglyceride is found in all foods containing ________FatLinolenic and linoleic acids are bothessential fatty acidsEssential Fatty Acids (FA) cannot be___________ by the bodymadeLinoleic Acid and the Omega-6 Family (polyunsaturated)-Can make arachidonic acid, which is a conditionally essential fatty acid -Must be supplied by food -Can make EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), important for eyes, brain and heart -Deficiency associated with depression, growth retardation, reproductive failure and neurological problems -supplied primarily by vegetable oilsEPA and DHA are two long-chain omega-3 fatty acids that can besynthesized in the body's cells from linolenic acidRich sources of preformed EPA and DHA in foods:fatty fish (i.e. salmon), eggs from chickens fed omega-3 fatty acidsEicosanoidsMade from longer omega-3 and omega-6 fatty acidsEach eicosanoid plays a role in regulating ________ within the bodyactivityspecific type of eicosanoid:ProstaglandinsEPA eicosanoids (omega-3):decrease BP, prevent clot formation, protect against irregular heartbeats and reduce inflammation.NSAID's (Aspirin, Ibuprofen) inhibit formation of:prostaglandinsFatty Acid DeficienciesRare - Adequate intake is met by small amounts -May occur in infants and children with low-fat dietsHydrogenation stabilizes _______ by adding ______, thus converting them to _____________ (more resistant to oxidation).polyunsaturated fats, hydrogen, saturated fatty acidspartial hydrogenationproduces C=C double bonds where the position of hydrogen atoms shifts from being on the same side (cis) to opposite sides (trans).Diets rich in trans fatty acids or saturated fats are astrong risk factor for heart disease.Unsaturated fats-Liquid at room temperature -Spoil more quicklySaturated fats-Solid at room temperature -More resistant to oxidation -Alters texture-flaky crustsHow to protect from oxidation:1.Seal from oxygen 2.Add antioxidants 3.Hydrogenate 4.RefrigeratePhospholipidscontain glycerol, two fatty acids and a phosphate group with a molecule of choline and are used as emulsifiers in the food industryPhospholipids arepartially hydrophobic (non-polar or water-insoluble) and partially hydrophilic (polar or water-soluble).sterolsthe starting material for some hormones, and make up the structural component of cell membranes, bile acids, sex hormones, adrenal hormones and vitamin DLiver produces 800-1500 mg cholesterol per day (endogenous) ofsterolsWhite Fat-Stores energy in the form of fat for other cells to utilize -Long-term storage form of energyBrown Fat-Releases stored energy as heat (uncoupling proteins) -Protects infants who cannot shiver from cold but depot decreases with age -Large # of mitochondria makes them appear brown -White adipocytes can transform to brite cells in certain biological environments. -Physical activityBrown fat (and brite cells) may __________ energy utilization, thus assist with _____________increase, weight lossUncoupling proteins found in brown fat and brite cells (due to increased mitochondria) willgenerate heat without generating ATP (like white adipose tissue), thus are "energy wasting".mouthSome hard fats begin to melt and salivary glands release Lingual LipasestomachChurning action mixes fat with water and acid.Lingual Lipase ( acid stable) begins to initiate fat digestion. Not appreciable at this point. Gastric lipase present, small roleS.I.CCK signals Gallbladder to secrete bile.Bile flows in from Gallbladder to emulsify fat, Pancreatic lipase flows in from the pancreas and intestinal lipase is present resulting in monoglycerides, Glycerol, and fatty acids that can then be absorbed. Sterols are absorbed as is. Phospholipids are hydrolyzedL.I.Some fat and cholesterol is trapped in fiber exits the body in the feces.Triglycerides are hydrolyzed intomonoglycerides and two fatty acids or a glycerol and 3 fatty acids by pancreatic lipases.Lipid transport is made possible by a group of vehicles known aslipoproteinsthe largest of the lipoproteins areChylomicronsChylomicrons travel from __________ the intestinal cell into the lymphatic system and enter into the blood system near the __________.inside, heartThe liver repackages lipids into two other types of lipoproteins for distribution in the body:The liver repackages lipids into two other types of lipoproteins for distribution in the body:VLDL and HDLChylomicrons(high in TG) DIETmade: in the small intestine cells function: Bring TG into body's cellsVLDL(50% TG)made: Liver, endogenous TG funtion: Bring TG into body's cellsLDL (high in cholesterol)made: From VLDL fragments function: Bring cholesterol to body's cells health implications: If high, increase risk for heart diseaseHDL(high in protein)Also contains Cholesterolmade: Liver and SI function: Bring cholesterol back to the liver (possible excretion) health implications: If high, decreases risk for heart diseaseTotal cholesterol<200 mg/dL Desirable, 200-239 mg/dL Borderline High, 240 and above HighatherosclerosisDevelops when plaque builds on artery walls and leads to inflammationAdvanced Atherosclerosis-Buildup with clots and platelets -Blockage can lead to tissue deathWhen plaque gets loose, it causes:Thrombosis and EmbolismThrombosis-Blood clot sticks to artery -grows large enough to close off blood vessel. -Leads to heart attack or myocardial infarction.Embolism-Blood clot breaks free lodges in a small artery -Shuts off blood flow to tissuesFat AMDR20-35%% Saturated, MUFA's and PUFA's7-10%, 10-15%, 10%Daily values reccomended of fat-65 g fat based on 30% of 2000-kcal diet -20 g saturated fat based on 10% of 2000-kcal diet -300 mg cholesterolMonounsaturated Fatty Acids (MUFA) sources:-Oils (canola, olive, peanut, sesame) -Avocado -Nuts (almonds cashews, filberts, hazelnuts, macadamia nuts, peanuts, pecans, pistachios) -Olives -Peanut Butter -Seeds (Sesame)Omega 6 Fatty acids sources-Margarine (non-hydrogenated) -Oils (corn, cottonseed, safflower, soybean) -Nuts (pine, walnuts) -Mayonnaise -Salad Dressing -Seeds (pumpkin, sunflower)Trans fatty acids (bad for you) sources-Fried foods (hydrogenated shortening) -margarine (hydrogenated or partially hydrogenated) -Nondairy creamers -Many fast foods -Shortening -Commercial baked goods (including doughnuts, cakes, cookies, etc.) -Many snack foods (including microwave popcorn, chips, crackers)Saturated fatty acids (bad for you) sources-Bacon -Butter, lard, cream cheese, sour cream -Chocolate -Coconut -Cream, half-and-half -Meat -Milk and milk products (whole) -Oils (coconut, palm, palm kernel) -ShorteningReplacing saturated fat and trans fat with monounsaturated fat and polyunsaturated fat is one of the most effective dietary strategy in preventing:heart diseaseAmino acids are made of C,H, and O (just like CHO and lipids) but also containNitrogenprotein is denatured when it iscooked, digested7 roles of proteins in the body1.Structural materials for growth and maintenance 2.Act as enzymes 3.Act as hormones 4.Help maintain the body's fluid balance 5.Help maintain acid-base balance within the body fluids 6.Serve as transporters 7.Serve as antibodies to defend the body against diseaseenzymes are involved inBuilding substances, Breaking substances down, Transforming one substance into anotherproteins accept and release H+ atoms acting as abufferProtein turnoveris the continual building up and breaking down of proteinnitrogen balanceused to determine protein requirements(+) N balance: N in > N outperiods of growth (growing child pregnant woman)(-) Pro balance: N in < N outperiods of catabolism (astronaut, surgery patient)N Equilibrium: N in = N outBody homeostasis (healthy adult)Deaminationthe first step in sacrificing protein for energy. Produces ammonia + keto acidLiver ________ urea into the blood, Kidneys ______ urea out of the bloodreleases, filterQuality of a proteinmeasured by AA content, digestibility, and the ability to support growthHigh quality proteins provide enough of all the ___________ in relatively the same amounts and proportions humans require.essential AA'sdigestibility of a proteinis a measure of the amount of AA absorbed from a given protein intakeDigestibility also dependent on factors such as ___________ or ____________phytic acid and malliard reactionPDCAASProtein Digestibility Corrected Amino Acid ScoreLimiting AAThe essential AA found in the shortest supply relative to the amounts needed for protein synthesis in the bodyProtein AMDR10-35%Minimum RDA for a proteinMinimum protein intake necessary to avoid a progressive loss of lean body mass as reflected by N balanceWhey-May increase protein synthesis slightly when combined with strength training -High in leucine which has been shown to increase muscle synthesis. -Too much protein can lead to diarrhea -Protein powders can contain high levels of heavy metals*Heart disease can be caused byanimal protein/ saturated fatscancer can be caused byanimal pro assoc. with colon cancerexcess protein can be linked to-CVD -Kidney stones -Osteoporosis -Some types of cancerKwashiokor - Protein Deficiency-Children 1-3 years old -Some weight loss -Edema -Enlarged fatty liver -Prone to infections, rapid heart beat, excess fluid in lungs, pneumonia, septicemia, and water & electrolyte imbalancesMarasmus - Energy deficiency-Chronic food deprivation/ starvation -Impairs brain development & learning -Muscle wasting, including heart -Severe weight loss -Growth is restricted -Prone to dehydration, infections and blood clotting5 Basic components of physical fitness1.Cardiorespiratory endurance 2.Muscle strength 3.Muscle endurance 4.Flexibility 5.Body compositionCardiorespiratory enduranceAbility to sustain cardiorespiratory exercise for an extended length of timemuscle strengthAbility to produce force for a brief period of timemuscle enduranceAbility to exert force over a long period of time without fatigueflexibilityRange of motion around a jointFITT principle- design a fitness program1. Frequency - how often activity is performed 2. Intensity - degree of difficulty at which activity is performed 3. Time - how long activity is performed 4. Type - specific activity being performedbenefits of physical activity1.Increases Psychological Well-Being 2.Promotes Healthy Body Weight 3.Reduces Injuries 4.Reduces risk of Chronic Disease 5.Improved Immune SystemGlycolysis-Pathway that does not require oxygen -Lactic acid can be produced anaerobically -Minimal ATP production, but next phaseAerobic metabolismPyruvate to acetyl CoA - lots of energyEnergy sources requiring oxygenGlucose/glycogen, fatty acidsCarbohydrate loading is a strategy to __________ glycogen storesmaximizeBest fuels for exercise1. Carbohydrates -Glucose, sucrose and maltodextrin are quickly absorbed 2. ProteinsIron-Necessary for energy metabolism and oxygen transport -Low levels = early fatigue and weaknessCalcium-Athletes susceptible to broken bones and fractures -Adequate calcium needed for bone health, skeletal and heart muscle contraction, and hormone and neurotransmitter activity during exercise -Calcium is lost in sweatwater intoxication and hyponatremiaSymptoms: Confusion, difficulty breathing, headache, nausea, vomiting, seizure, coma and death. occurs in: Marathon runners, Infants-Over diluted formula or too much free water, Psychotic patients-Taking meds that produce water cravings.metabolismis the sum total of all of the chemical processes needed in living organisms to maintain life. Metabolic reactions occur in the cells.anabolicReactions in which small molecules are put together to build larger onesanabolic reactionsMaking of glycogen, triglycerides and proteins (require energy).catabolic reactionsReactions in which large molecules are broken down to smaller onescatabolic reactionsBreakdown of above releasing energy-much captured in ATP.enzymesprotein catalysts that speed up or assist chemical reactionscofactorsorganic or inorganic substances (minerals) that facilitate enzyme actioncoenzymesorganic molecules (not protein) that function as enzyme helpers. Without these, enzyme function cannot happenduring catabolism-bonds between atoms are broken -energy is releasedTurning macronutrients into ATP Step 1:Glycolysis=the process of breaking down glucose and turning it into pyruvate.Turning macronutrients into ATP Step 2:Intermediate Step = Pyruvate Acetyl CoATurning macronutrients into ATP Step 3:TCA Cycle = A way to take small molecules like Acetyl CoA and tear H's off of themTurning macronutrients into ATP Step 4:Electron transport chain = A way to take all of the H's from steps 1,2 & 3 and use them to make ATPglucose metabolismbegins with glycolysis, in which glucose is converted to a 3-carbon molecule, pyruvate.glycolysistakes place in cytosol of the cell; can function under anaerobic or aerobic conditionspyruvate-> lactatewhen energy is needed quickly, anaerobicpyruvate-> Acetyl CoAWhen energy is needed more slowly aerobiclactateis a 3-carbon compound produced from pyruvate during anaerobic metabolismAcetyl CoAis a two carbon molecule to which all energy yielding nutrients (glucose, amino acids, glycerol, fatty acids) converge when being metabolized for energy.When the body needs energy, it will send _________ through a set of chemical reactions called the________ (AKA Kreb's Cycle).acetyl CoA, TCA cycleIn the last step of this process, energized H+ is carried by _____ and ____ (co-enzymes), to enter the Electron Transport Chain (ETC)NAD, FADtriglyceride hydrolysis -> GlycerolJumps mid-way into the glycolysis pathway; can be converted to glucose or pyruvatetriglyceride hydrolysis -> fatty acidsBroken down into 2-carbon fragments that combine with CoA to form acetyl CoA"Fatty acid oxidation"Fatty acids are taken apart ____ carbons at a time. Known as2, fatty acid oxidationBroken down into 2-carbon fragments that combine with CoA to form:acetyl CoA "fatty acid oxidation"Any remaining ammonia is cleared from the body via ____________ in the liver and ___________ by the kidneysurea synthesis, excretionSome amino acids are converted to __________, then to ___________. These are called glucogenic amino acids because they can also be used to make _________.pyruvate, acetyl CoA, glucoseDietary carbohydrate is used as__________, thus sparing protein for other purposes, like building or repairing cells. This is known as the protein-sparing action of carbohydrates.energyFood does not give more or unlimited energy becausethe body regulates how much of the energy yielding nutrients can enter the TCA cycle.When you consume more calories than you need, your body will store it asglycogen and fatThe initial source of glucose during a fast, even an overnight fast, will be from _________stored glycogenafter the stored glycogen is depleted, the body uses other processes to convert ______ to _____________AAs to Glucose (glucogenic AAs)ketosisProlonged starvation will result in ketones spilling into blood and urine