Carbohydrates1. What are the functions of carbohydrates in the human body?Main source of energy for cellsSpare proteinAdd bulk to foodsProvide energy, fiber2. What is the difference between a simple and a complex carbohydrate? List the three disaccharides and the three monosaccharides.Simple carbohydrate: SugarsMolecule with 6 carbon atoms and oxygen and hydrogenComplex carbohydrates: Starches and fiberSometimes called polysaccharidesLong chains of sugar unitsDisaccharidesSucrose (glucose and fructose)Lactose (glucose and galactose)Maltose (glucose and glucose)MonosaccharidesGlucose- the body’s predominant fuelFructose- fruit sugarGalactose- one of the two components of the milk sugar lactose3. What is the difference between starch, fiber, and glycogen?Starch- plant sourcesFiber- Plant material—long chains of glucose molecules whose structure is resistant to enzymatic degradation (cellulose, hemicellulose, pectin)Glycogen- animal starch—configured in long chains of glucose molecules; the body’s storage form of carbohydrate4. What are the benefits of consuming high fiber foods?Liver uses blood cholesterol to make bilegallbladder stores bileIntestine: bile aids digestion, binds to fiberA little cholesterol in bile reabsorbed into the blood or fiber and bile excreted in fecesKeeps one more fullSlows down digestionHelps maintain healthy body weight5. What is lactose intolerance?Deficiency in the enzyme lactase where one can be nauseous, have diarrhea, and gas6. Explain how blood glucose is regulated (including which hormones are involved).After a meal, blood glucose risesPromotes and increase in insulin releaseInsulin promotes glycogen formationIn liver and muscleAfter a while, glucose levels fallsPromoting glucagon releaseGlucagon stimulates glycogen conversion to glucose from liver7. Compare and contract Type I and Type 2 diabetes mellitus. What are the long term side effects of the disease?Type 1—IDDMCharacterized by an immune response to pancreatic B cellsEventually the pancreas stops making insulinOften starts early in lifeType 2—NIDDMCharacterized by insulin resistance—the insulin is there, but it does not work to foster glucose uptake by the cellsOccurs later in lifeSome long term side effects include death8. What are the three carbohydrates currently used for biofuel production? Which of these is least efficient in the conversion of carbohydrate to ethanol with the current technology?Sucrose (sugarcane, easiest)Starch (corn kernel)Cellulose (corn stalk, grass, wood, most difficult)Least efficient:Lipids1. What are the functions of lipids in our bodies and in foods?Natures way of condensing energy storesAlso insulates/protects organsSource of calories (9kcal/gram)Flavor and tenderness of foodSlows stomach emptying—more satiatingSource of essential fatty acids2. What are the three main types of lipids?TriglyceridesPhospholipidsSterols3. How are lipids digested/absorbed in the body? How are they transported from the gastrointestinal tract to the liver? What happens to them in the liver?DigestionDepends 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 lipoproteinsChylomicronsEnter lymph and then blood streamTransport as LipoproteinsChylomicrons—from intestine to bodyOther produced in liverVLDLs (Very Low Density Lipoproteins)LDLs (Low Density Lipoproteins)Both take TG and cholesterol to bodyHDLs (High Density Lipoproteins)Scavengers of cholesterol, brings it back to liverIn the liver they make bile then goes to the gallbladder where it is stored until it is needed for digestion and absorption of fats4. What are the differences between saturated and unsaturated fatty acids in terms of chemical structure, where they are found in our diet, and their impact upon human health?Saturated Fatty AcidChemical structure: A fatty acid carrying the maximum number of hydrogen atomsFound in: animal fatsImpact:Unsaturated Fatty AcidChemical structure: A fatty acid with less than maximum hydrogen atoms (monosaturated fatty acid, polyunsaturated fatty acid)Found in: vegetable oils, olive oilImpact:5. What is trans fat? Where is trans fat found in the human diet? Why are we advised to eat minimal trans fat?Fatty acids with unusual shapesArise when polyunsaturated oils are hyrodenatedAdvantage: Control consistency and oxidation of fatsDisadvantage: Increase LDLFound in margarines, shortenings, baked goods6. What are the two essential fatty acids? Where are they found in our diet? Why is it important to have the proper balance of these two fatty acids in the diet?Omega-3 Fatty AcidsOmega-6 Fatty Acids (vegetable oil more than omega-3 fatty acids)Made in limited amounts in the bodyAbundant in fish oilsPrevent against irregular heartbeatsMay reduce inflammationEssential for normal infant growth and developmentMay support immune systemMay inhibit cancer7. What is the function of a lipoprotein? List the three main types of human lipoproteins and describe the function of each.Used to assess risk of heart diseasesTotal cholesterolLDLs associated with increased riskLess healthy, want lowHDLs associated with decreased riskHealthy, want high8. What are the desirable values for total cholesterol, HDL and LDL in our blood?Total cholesterol: <200HDL: >40LDL: <130Proteins1. What the functions of proteins in the body? How much protein does the average person need?Build new tissueFunctional unit (a few to thousands amino acids)EnzymesHormonesAntibodiesPhysiology/metabolismFluid and electrolyte balanceAcid-base balanceEnergyTransportation (e.g. Lipoproteins)Blood clottingThe DRI recommendation for protein intake depends on size and stage of growthDRI recommended intake is 0.8 grams per kilogram of body weightMinimum is 10 percent of total caloriesAthletes may need slightly more (1.0 gram per kg)2. What is an essential amino acid? What are the nine essential amino acids?Essential amino acid- not made by usHistidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine3. What are marasmus and kwashiorkor? What causes each? What are the symptoms of each?MarasmumChronic inadequate food intakeInadequate energy, vitamin, mineral, and protein intakePerson is shriveled and lean all overKwashiorkorSwollen belly and
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