TOPIC4:NUTRITIONpart2

Learningoutcomes

1.  Iden5fythefunc5onsofnutrients.2.  Compareintracellularandextracellular

diges5on.3.  Describethefunc5onofdiges5vesystemsin

animals.4.  Iden5fytheneedsofnutri5oninplants.5.  Describethetransporta5onofwaterand

nutrientsinplants.

Diges1veSysteminAnimalsAnimals diges5ve system could be categorizedbasedontheirea5ngstrategies.

Typesofanimals:1.  Herbivores:mainlyonplantsoralgae.2.  Carnivores:mostlyeatotheranimals.3.  Omnivores: consume animals as well as

plants.

Describethefunc5onofdiges5vesystemsinanimals.

Tube-Within-a-TubeBodyPlan

•  mostanimalshaveacompletetube-within-a-tube(completediges5vesystem)

•  ithasamouthandanus.•  Thisinnertubeisseparatedfromthebodywallbythecoelom/cavity.

•  similaracrossanimalspecies.

Tube-Within-a-Tube

1.Ingestsfood

2.Diges1on:Breaksdown

foodintosmallermolecules

3.Absorbssmallmolecules/nutrients

4.Eliminatesindiges1ble

waste

4Essen5alfunc5onsindiges5vesystem

Human Digestive System: Draw and Label it!

[structure]

• [func5ons]

PreparethisMAP

1.Mouth

•  thediges5vetractbeginswiththemouth.

•  teethmechanicallytearandgrindfood,

•  salivaryglandsreleasetheenzymeamylaseintothemouthtodegradecarbohydrates.

•  Theground,par5ally-digestedfoodmaterialthatisswallowediscalledabolus.

2.Pharynx•  thediges5veandrespiratory

systemsshareacommonpassagebehindthemouthcalledthepharynx.

•  TheflowoffoodthroughthepharynxèesophagusisassistedbytheepigloWs,whichcoverstherespiratorypassage.

•  Therhythmiccontrac5onsoftheesophagus,calledperistalsis,movefoodtothestomach.

Watchthis:hYp://bit.ly/1JnOxk5

3.Stomach

•  proteinsinfoodaredigested.

•  lowpHandtheenzymepepsinaccomplishthediges5onofproteinstopolypep5des

•  Peristalsismovesfoodthroughthestomach

•  asphincterregulatestheflowofdigestedfoodintotheintes5ne.

Peristalsismovefood(bolus)throughthestomach

Regulatestheflowofdigestedfoodintointes5nethroughtheduodenum

4.SmallIntes1ne•  Thedigestedfoodmaterialthe

exitsthestomachandentersthesmallintes5neiscalledchyme.

•  Smallintes5nedividedinto3parts:1.  Duodenum2.  Jejunum3.  Ileum(mostabsorp5on)Thesmallintes5neprovides2func1ons.

1.  Addi5onaldiges5onoffoodmaterial2.  Absorp5onofnutrients

•  3addi5onalorgans(accessoryorgans)thatassistthesmallintes5ne:

1.  Liver2.  gallbladder,3.  pancreas

•  Theliverproducesbiletoemulsifyfatsfordiges5onandabsorp5on.

•  Excessbileisstoredinthegallbladder.

•  Thepancreasproducesajuicethatcontainssubstancesthatenhancediges5on:

1.  Sodiumbicarbonate,toincreasechymalpH

2.  Pancrea5cenzymes/diges5veenzyme

•  Thereareseveralpancrea5cenzymes:

1.  Pancrea5camylasetodigeststarches2.  Trypsintodigestproteins3.  Lipasetodigestfats4.  Nucleasetodigestnucleicacids-nucleo5des5.  Erepsin(pep5dase)todigestpep5des–amino

acids

•  Absorp5onofthedigestednutrientsisfacilitatedbyhair-likevilliintheintes5ne.

•  Thevillihavemicrovillitogreatlyincreasetheirsurfaceareaforabsorp5on.

•  Lacteal(lympha5ccapillary)absorbeddigestedfats.

5.Liver

Avarietyof

func1ons:

Removalofpoisonsandtoxinsfromtheblood

Produc1onofplasmaproteins

Destruc1onofoldredbloodcells

Produc1onofbile

Storageofglucoseasglycogen

Produc1onofurea,anitrogenous

waste(mainlyformprotein/aminoacidmetabolism)

•  Theliverfunc5onsarecarriedout,asbloodfromtheintes5nestravelstotheliverthroughthehepa5cportalsystem.

Liverdisorders

•  Disordersoftheliver.

–  Jaundice:anexcessiveconcentra5onofbilepigmentsintheblood.

–  Hepa55s:viralinfec5onoftheliver.

–  Duringcirrhosis(eg:inalcoholicpa5ent),liver5ssuechangestobecomefaYyandthennon-func5onalscar5ssue.

6.Pancreas

Thepancreasfunc5onsasbothan

endocrineandexocrinegland.

TheENDOCRINEfunc5on:

secre5onofinsulinandglucagonintothebloodstream.

TheEXOCRINEfunc5on:

secre5onofpancrea5cjuiceintothesmallintes5ne.

7.LargeIntes1ne

•  Thelargeintes5neabsorbswater,salts,andsomevitamins.

•  Theappendixisapouchofthelargeintes5ne.

•  Bacteriainthelargeintes5nedigestremainingmaterialpriortoexcre5onofthewastes(feces)throughtheanus.

STOMACHINRUMINANT

•  Ruminantisanimalsthathaveastomachwithacompartmentcalledtherumen.

•  Therumencontainssymbio5cbacteriathathelptheseherbivoresdigestplants.

•  Whenanimalschewcud,theyarechewingthepar5ally-digestedrumenproduct.

•  plantswhichcontainhighpercentageofcellulose;digestedbyenzymecellulase

Whatiscud?

Cud is a por5on of food that returns from a ruminant'sstomachtothemouthtobechewedforthesecond5me.it is a bolus of semi-degraded food regurgitated from there5culorumenofaruminant.Cud is produced during the physical diges5ve process ofrumina5on.

1. Iden5fytheneedsofnutri5oninplants.2. Describethetransporta5onofwaterandnutrientsinplants.

PlantNutri1on

•  requireonlyinorganicnutrientstosurvive.

•  converttheseinorganicnutrientstotheorganiccompoundsneededforlife.

•  Someinorganicelementsareessen5al,meaningthatplantshaveanabsoluterequirementforthoseelements.

•  Theessen5alnutrientsaredividedintotwocategoriesbasedupontheirrela5veconcentra5onsinplant5ssues.

1.  Macronutrientsareelementsthatare

requiredinlargeamounts.2.  Micronutrientsarerequiredinsmall

amountsforspecializedfunc5ons.

PlantNutri1on

•  Thereare9macronutrients.1.  Carbon2.  Hydrogen3.  Oxygen4.  Phosphorus5.  Potassium6.  Nitrogen7.  Sulfur8.  Calcium9.  Magnesium

•  Thereare7micronutrients,whichserveprimarilyasenzymecofactors.1.  Iron2.  Boron3.  Manganese4.  Copper5.  Zinc6.  Chloride7.  Molybdenum

•  Deficienciesinoneormoreofthesenutrientscanstuntplantgrowth.

UptakeofNutrient-ladenwater

•  Manyplantstructuresandfunc5onsareadaptedtolimitedamountsofwateranddissolvedmineralions

•  Amountofwaterandmineralsavailableforplantstotakeupdependsonthecomposi5onofsoil

•  Therootsystemsofvascularplantsabsorbwaterandmineralinthesoilfornutrients

UptakeofWaterandNutrientbyRoot

Howplantrootsabsorbwater?

• Casparianstrippreventwaterandsolutesfrompassingbetweencellsintovascularcylinder.

• Thewater-impermeableCasparianstripforceswaterandsolutetomovethroughendodermalcells,notpastthem.

• Waterandsolutesmustflowthroughcells

• Transportmechanismsinthecellscontrolwaterandnutrientuptake.