The Digestion System Ch 35 Guide Mechanical & Chemical Breakdown Of Food for energy

The Digestion System

Ch 35 GuideCh 35 Guide

Mechanical &Mechanical &

Chemical BreakdownChemical Breakdown

Of Food for energyOf Food for energy

I 1) Mouth: MechanicallyMechanically breaks up foodbreaks up food

ChemicallyChemically digests digests CarbohydratesCarbohydrates Basic pHBasic pH Enzyme amylase Enzyme amylase

from salivary from salivary glandsglands

Wets & formsWets & forms “bolus”“bolus”

2. StomachMechanicallyMechanically

churns churns Stores Stores foodfoodChemicallyChemically

digestsdigests ProteinsProteins Acid pHAcid pH Enzyme PepsinEnzyme Pepsin From PancreasFrom PancreasMucus Lining Mucus Lining

prevents digestion prevents digestion of itself !of itself !

3. Small Intestine AbsorptionAbsorption

of foodof food

Digestion Digestion ofof Lipids (fats)Lipids (fats) Carbohy-Carbohy-

dratesdratesUses Lipase & Uses Lipase &

Amylase from Amylase from the pancreasthe pancreas

4. Large Intestine

Absorbs Absorbs water & water & vitaminsvitamins

No DigestionNo DigestionEliminates Eliminates

wasteswastes

Barium Enema: window to the intestines:

5. Salivary Glands: MakesMakes the the salivary juicessalivary juices

Contains Contains amylase amylase enzymesenzymes

Basic pHBasic pH For the For the

digestion of digestion of carbohydratescarbohydrates

6 Liver:. Makes bile & Stores sugar as glucagon

No food passes through the liverNo digestion takes place in the liver

Gall Bladder stores bile

7.Gall Bladder: Stores bile made by the liver

Bile emulsifies Bile emulsifies fatsfats

Makes them Makes them water solublewater soluble

In small In small intestineintestine

No food passes through the gall bladderNo digestion takes place in the gall bladder

Carter’s Little Liver Pills: cure=all

Liver also Liver also cleanses the cleanses the bloodblood

Carter’s pills Carter’s pills claimed to cure claimed to cure constipation, constipation, headaches, skin headaches, skin problems???problems???

8.Pancreas makes digestive juices:Enzymes & Acids or bases

No Digestion in the Pancreas ! No food passes through here

9. Appendix: vestigial organ

I 2-3. Types of Digestion:Intracellular:Intracellular: Inside a cellInside a cell Food vacuolesFood vacuoles Small particlesSmall particles Examples:Examples: Amoeba, Amoeba,

ParameciumParamecium

Extracellular:Extracellular: In a sack or In a sack or

tubetube Larger foodLarger food Then absorbed Then absorbed

into a cellinto a cell HumansHumans

II. Digestion Products:ProteinsProteins

Carbo-Carbo-hydrateshydrates

LipidsLipids

Amino acidsAmino acids subunits subunits Muscle,enzymes,HbMuscle,enzymes,Hb Last use for foodLast use for food

Simple sugar (glucose)Simple sugar (glucose) Quick energy foodQuick energy food 11stst used used

Fatty acids & glycerolFatty acids & glycerol Long term food, Long term food,

insulation,protectioninsulation,protection 22ndnd used for food used for food

III 1. Digestion:IsIs Breaking down foodBreaking down food physically & chemicallyphysically & chemically

ForFor The purpose of distributing small The purpose of distributing small

water soluble particles to the cells water soluble particles to the cells for energyfor energy

III 2. Homeostasis Maintaining Maintaining

balancebalance ““homo”=samehomo”=same ““stasis”=statestasis”=state By constant By constant

adjustmentsadjustments For survivalFor survival

pH= Proper acid or base levels

Basic Basic = > 7 = > 7 Digestion of Digestion of

carbohydratescarbohydrates & lipids& lipids AcidicAcidic= < 7= < 7 Digestion of Digestion of

proteins in the proteins in the stomachstomach pH 2 7 8 1 0 12

4.Properties of Enzymes ProteinsProteins CatalystsCatalysts Speed reactionsSpeed reactions Work fastWork fast Denature at high Denature at high

temptemp

Enzyme-Substrate complex

Substrate

Active site = where the substrate( reaction molecule)connects toenzyme

Active Site

Enzyme

Lock & Key ModelOne One enzymeenzymefor every for every

substratesubstrateunique fitunique fit

Substrate

Enzyme

Enzymes are pH specific

Different enzymesDifferent enzymes Different body areasDifferent body areas Different optimum pHDifferent optimum pH

StomachStomach= acid pH= acid pH

Uses Uses PEPSINPEPSIN

MouthMouth= basic pH= basic pH

Uses Uses AMYLASEAMYLASE0

10

20

30

40

50

60

70

80

90

100

pH 2 pH 4 Ph 6 pH 8

Stomach

Blood

Mouth

Bile: Made in Liver Stored in Gall Bladder

Emulsifies Emulsifies fatsfats

Makes them Makes them water solublewater soluble

In small In small intestineintestine

Villi: Small intestine absorb food

Many “finger-like” villi maximize surface area

8.Peristalsis: ContractionsContractions

of the of the Digestive Digestive system system

Moves foodMoves food downdown

Controlled by Controlled by the autonomic the autonomic nervous nervous systemsystem

Control of Digestion by the Nervous System