1. 6.1 The Human Digestive System

2. Think about eating – why do we need to eat? What does food provide us?
Think on the last food you ate. What happens to the food we eat? If you at 3lbs of food during your last meal – account for all 3 pounds, where does it “go”?
YES or NO You need gravity to digest your food.
YES or NO Heartburn is when your heart hurts.
YES or NO Stomach acid is there to digest food.
YES or NO The stomach absorbs nutrients.
YES or NO Feces is mostly bacteria.
YES or NO You produce vitamins in your digestive system.

3. What are the 3 organic polymers that you need to ingest and digest
What are the 3 organic polymers that you need to ingest and digest? What are their monomers? How is each polymer used by your cells?

4. 4 “Stages” of Digestion Ingestion Digestion Absorption
Transport &Elimination

6. Mechanical digestion vs. Chemical digestion
Mechanical : the physical breakdown of food
Examples: chewing, stomach churning
Chemical : use of enzymes to carry out hydrolysis (breakdown of food)
Examples: amylase enzyme in the mouth and small intestine

9. Digestive System Terms
Surfactant: organic liquid substance that contains enzymes or other molecules that help chemical processing.
Gland: an organ that secretes a particular chemical substance
Duct: a channel or tube that material can pass through

10. http://highered. mcgraw-hill

15. Structure of the Small Intestine

17. Structure of Villi & Microvilli

18. Micrographs of Villi and Microvilli
Lumen of Small Intestine
Microvilli

19. What structural features of the villus make it suitable for absorption of nutrients?

21. Egestion vs. Excretion
Excretion: getting ride of waste formed from chemical reactions during metabolic activity.
Ex: urine, sweat
Egestion: removal of undigested food or feces from the gut.
Ex: indigestible matter that is never absorbed into cells.

22. Summary of Nutrient Transport in Absorption
Note: “Co-transport” = Active Transport