1. Absorption of Nutrients
Section 9.5

2. Absorption of Nutrients
Learning Goal: To learn how nutrients are absorbed by the small intestine, into the bloodstream, and transported to our body cells.
Success Criteria:
I know I am succeeding when I can…
differentiate between passive and active transport
describe the different types of active transport

3. Absorption in the Small Intestine
all nutrients (once digested) make their way through the mucosa of the small intestine and into the capillary networks in the villi
there are several mechanisms of transport

4. Passive Transport
passive transport: the movement of materials across a cell membrane without the use of energy from the cell

5. Passive Transport Cont’d…
diffusion: substances move across the cell membrane from an area of higher concentration to an area of lower concentration (ex. small amino acids can diffuse into the bloodstream)

6. Passive Transport Cont’d…
osmosis: the diffusion of water molecules across a selectively permeable membrane, from an area of higher concentration (of water molecules) to an area of lower concentration (ex. water is absorbed in the large intestine by osmosis)

7. Passive Transport Cont’d…
facilitated diffusion: transport proteins speed up the movement of molecules that already move across the cell membrane (ex. some carbohydrates)

8. Active Transport
active transport: energy is required to move molecules through transport proteins across the membrane
used to transport molecules that are too large to diffuse through the cell membrane on their own and molecules (or ions) with an electrical charge that prevents diffusion across the membrane

9. Passive and Active Transport

10. Absorption of Nutrients in Capillary Networks & Cells
once absorbed into the capillary networks by passive or active transport nutrients move through the bloodstream
the lacteals (small vessels of the lymphatic system) carry fats through the lymphatic system, eventually reaching the bloodstream
nutrients are then transported from the bloodstream into the body cells by passive or active transport

11. Absorption of Nutrients
Learning Goal: To learn how nutrients are absorbed by the small intestine, into the bloodstream, and transported to our body cells.
Success Criteria:
I know I am succeeding when I can…
differentiate between passive and active transport
describe the different types of active transport

12. Homework
9.5 questions # 1, 2a, 3, 5-9