240 likes | 374 Views
Introduction to Nutrition The Adventure of Ingested Food. To obtain nutrients in food!. • • • • • •. • • • •. ENERGY. Carbohydrates Proteins Lipids (fats) Water Vitamins Minerals. Survive Growth Physical activities Maintenance: - constant body temp. - biological processes.
E N D
IntroductiontoNutrition TheAdventureofIngestedFood
Toobtainnutrientsinfood! • • • • • • • • • • ENERGY Carbohydrates Proteins Lipids(fats) Water Vitamins Minerals Survive Growth Physicalactivities Maintenance: -constantbodytemp. -biologicalprocesses Metabolism:chemicalreactionsthatthebodyneedstoperforminordertostayalive Therearetwo(2)typesofchemicalprocesses: Catabolism–breakingdownofmaterialsinanorganism(e.g.digestionoffood) Anabolism–buildingoflargeandcomplexmoleculesfromsimplerones
Factorsdeterminehowmuchananimalneedstoeat: Bodysize:largerbodyneedsmoreenergytostayalive Physicalactivity:muscleburnsmoreenergywhenactivityismorerigorous Gender:malestypicallyarelargerinsize&havegreateramountofmusclemass Age:metabolicratedecreasewithage(lossofmusclemass) Heredityfactors:someindividualhaveanaturallyhighmetabolicrate Basalmetabolicrate:theminimumamountofenergyrequiredtokeepyoualive Male: BMR=[66+(13.7xmassinkilograms) +(5xheightincentimeters) –(6.8xageinyears)]x4.18 Female: BMR=[655+(9.6xmassinkilograms) +(1.8xheightincentimeters) –(4.7xageinyears)]x4.18 Toaccountforthelevelofactivity: a.Littleornotexercise b.Some(1-3days/week) c.Moderate(3-5days/week) BMRx1.2 BMRx1.375 BMRx1.55 BMR=unitiskJ 1000calories(C)=4180J
Carbohydrates:aresugarsandtheirderivatives(i.e.otherformsofsugars)Carbohydrates:aresugarsandtheirderivatives(i.e.otherformsofsugars) mainsourceofenergyofthehumanbody madeupcarbon,hydrogenandoxygen threemaintypes:monosaccharides,disaccharides&polysaccharides Monosaccharides:aresimplesugars examplesincludeglucose,fructose,galactose themolecularformulaisC6H12O6 themolecularstructureiseitherlinearorringform glucose Disaccharides:whensimplesugarspairupformingsugarderivatives examplesincludemaltose,sucrose,lactose glucose+glucose=maltose+H2O glucose+fructose=sucrose+H2O glucose+galactose=lactose+H2O
Polysaccharides:arelongchainsofsugarunits exampleincludecellulose,amylose(starch),glycogen cellulose–verylongchainofglucoseunits,providestructureforplantcellwalls starch–polysaccharidesofmostlyglucoseunits,storeenergyinplantcells glycogen–polysaccharidesofglucoseunits,storeenergyinanimalcells glycogen (highlybranched) cellulose (nobranching) amylose(somebranching)
Proteins:arechainsofaminoacids;theyarevariableinshape,size,functionProteins:arechainsofaminoacids;theyarevariableinshape,size,function examplesincludehormones,organelles,hemoglobin,antibodies thereare20aminoacidsfromwhichproteinsarebuilt humanbodycanmaketwelve(12)oftheseaminoacids,soweneedto obtaintheothereight(8)fromfoodsources Animalsources:meat,eggs,fish,cheese Plantsources:beans,lentils,seeds,nuts molecularstructure: Peptidebond–H2Oiscreated/released
Lipids:areconcentratedsourceofchemicalenergy functions:insulatethebody,absorbvitamins,formcellmembranes commontypesoflipidsarefatsandoils molecularstructure:glycerol+3fattyacids=triglyceride therearetwo(2)formsoftriglyceride:saturatedandunsaturated Saturated: singlebonds=straightchain solidatroomtemperature Unsaturated: doublebonds=kinks liquidatroomtemperature healthier triglyceride
Food Ingestion MechanicalDigestion (physicalbreakdownoffood) •chewing(mouth) •churning(stomach) •segmentation(intestine) Propulsion •swallowing(oropharynx) •peristalsis(esophagus& intestines) Bolus Chyme ChemicalDigestion Absorption (chemicalbreakdownoffood) •lipids,starches •largemolecules •proteins arebrokendownfurther intotinymoleculesby enzymes&bodychemicals Viabloodvessels(capillaries) •nutrients,vitamins •water Feces Defecation/Egestion
oralcavity salivaryglands mouth tongue Mechanicalbreakdownoffood: •teeth,tongue Chemicalbreakdownoffood: •saliva,amylase
periodontalmembrane enamel dentin premolars molars uvula gingiva canines incisors wisdom tooth lip crown root tongue frenulum Functionofyourteeth: • • • • incisors:slicing&gripping canines:ripping&tearing premolars:bitting&tearing molars:grinding
SwallowedFoodbolus oralcavity pharynx esophagus mouth tongue Peristalsispushesthebolus towardsthestomachviamuscle contractionoftheesophagus
oralcavity pharynx mouth tongue esophagus stomach Gastricgland secretemucus& gastricjuicesto digestbolus gastricpits
oralcavity pharynx esophagus mouth tongue stomach smallintestine largeintestine
oralcavity pharynx esophagus mouth tongue stomach smallintestine largeintestine rectum anus
oralcavity pharynx esophagus stomach smallintestine mouth tongue liver gallbladder common bileduct Liversecretesbile •biledigestfat largeintestine rectum anus
oralcavity pharynx esophagus mouth tongue Pancreas -digestlargemolecules, -neutralizestomachacid Spleen -removesoldRBC -storesWBCthatguard againstinvaders liver gallbladder pancreas rectum stomach spleen smallintestine largeintestine anus