Post on 18-Dec-2015
Think about sliding a warm, tasty slice Think about sliding a warm, tasty slice of cheese pizza into your mouth. You of cheese pizza into your mouth. You take a bite, chew, and swallow. You take a bite, chew, and swallow. You probably aren't saying to yourself, probably aren't saying to yourself, "There, I'm providing my cells with "There, I'm providing my cells with nutrients." However, that's exactly what nutrients." However, that's exactly what you're doing. But first, your digestive you're doing. But first, your digestive system must disassemble the pizza into system must disassemble the pizza into basic building blocks that your cells can basic building blocks that your cells can use.use.
Activity: Enzymes at WorkActivity: Enzymes at Work
Chew the saltine cracker 25 times Chew the saltine cracker 25 times and record the answers to the and record the answers to the following questions:following questions:
1) Was there a change in the taste as 1) Was there a change in the taste as you chewed it? What was the you chewed it? What was the change?change?
2) What do you think caused the 2) What do you think caused the change in the taste? change in the taste?
NutritionNutrition IngestionIngestion FoodFood DigestionDigestion Food--Food-->Nutrients>Nutrients
AbsorptionAbsorptionNutrientsNutrients
EliminationElimination WasteWaste
MacromoleculesMacromolecules
CarbohydratesCarbohydrates ProteinsProteins FatsFats Nucleic acidsNucleic acids
CHEMISTRY OF DIGESTIONCHEMISTRY OF DIGESTION
HYDROLYSISHYDROLYSIS: WATER AND : WATER AND ENZYMES BREAK DOWN LARGER ENZYMES BREAK DOWN LARGER MOLECULES INTO SMALLER UNITSMOLECULES INTO SMALLER UNITS– PROTEINS TO AMINO ACIDSPROTEINS TO AMINO ACIDS– CARBOHYDRATES TO SINGLE SUGARSCARBOHYDRATES TO SINGLE SUGARS– FATS TO 1 GLYCEROL AND 3 FATTY FATS TO 1 GLYCEROL AND 3 FATTY
ACIDSACIDS
http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html
Human DigestionHuman Digestion
Mechanical Digestion- Mechanical Digestion- Chops & Chops & grinds food into smaller piecesgrinds food into smaller pieces
Chemical Digestion- Chemical Digestion- Breaks the Breaks the chemical bonds within chemical bonds within macromolecule, producing smaller macromolecule, producing smaller subunits.subunits.
titleAlimentary tract
–Mouth
– Esophagus
– Stomach
– Small intestine
• Duodenum
• Jejunum
• Ileum
– Lg. Intestine
• (appendix)
Accessory
Structures
– Salivary
glands
– Liver
– Gall bladder
– pancreas
Online ActivitiesOnline Activities
Phsuccessnet.comPhsuccessnet.com– Activity 29.1Activity 29.1– Activity 29.2Activity 29.2
MouthMouth
Mechanical Digestion (teeth/ tongue)Mechanical Digestion (teeth/ tongue) Chemical Digestion Chemical Digestion
– Salivia– produces Salivia– produces amylaseamylase Breaks down carbohydratesBreaks down carbohydrates
PharynxPharynx
Bolus of food travels down throatBolus of food travels down throat EpiglottisEpiglottis
EsophagusEsophagus
PeristalsisPeristalsis pushes food down tube pushes food down tube into the stomach.into the stomach.
StomachStomach
RugaeRugae Gastric juices (mucus, HCl, enzymes) Gastric juices (mucus, HCl, enzymes)
meet bolus.meet bolus.– Proteins digested here.Proteins digested here.
Bolus --- ChymeBolus --- Chyme Sphincters Sphincters 2-6 hours to empty2-6 hours to empty
Small IntestineSmall Intestine
Long & narrowLong & narrow Absorption of most Absorption of most
nutrients takes nutrients takes place here.place here.
Duodenum Duodenum (breakdown of fats, (breakdown of fats, proteins, and proteins, and carbs)carbs)
Villi absorb Villi absorb nutrients.nutrients.
Large Intestine (Colon)Large Intestine (Colon)
Wide & shortWide & short Water is absorbed into body.Water is absorbed into body. Feces- undigested waste leaves in Feces- undigested waste leaves in
12-24 hours12-24 hours AppendixAppendix
Liver/ Gall BladderLiver/ Gall Bladder
Bile breaks down fats in the Bile breaks down fats in the duodonem.duodonem.
Liver makes bile.Liver makes bile. Gall bladder stores it.Gall bladder stores it.
PancreasPancreas
Secretes pancreatic juices into Secretes pancreatic juices into duodonem.duodonem.– Neutralizes chyme.Neutralizes chyme.– Breaks down carbs, proteins, and lipids.Breaks down carbs, proteins, and lipids.