1. Notes on Chapter 6.2 & 6.3 Movement through the Membrane

2. Homeostasis Examples:Examples: Body temperatureBody temperature SweatingSweating ShiveringShivering DehydrationDehydration Over-hydrationOver-hydration Definition: Process by which organisms maintain a relatively stable internal environment

3. III. Passive Transport A. Definition: Movement of molecules into and out of cell Movement of molecules into and out of cell that requires no energy that requires no energy B. Why?: Molecules are always in random motion! Molecules are always in random motion! Will always move from area of high Will always move from area of high concentration to low concentration to low

4. C. Types of passive transport:

5. 1. Diffusion a. Movement of ANYTHING from high concentration to low concentration »Does not require energy! Examples:Examples: Food coloringFood coloring Tea bagTea bag PopcornPopcorn PerfumePerfume

7. 2. Osmosis- Water Only! a. Definition: - Special kind of diffusion of water over - Special kind of diffusion of water over selectively permeable membrane selectively permeable membrane - From high concentration to low concentration - From high concentration to low concentration

8. -Important vocab (write on side margin) -Important vocab (write on side margin) Solute:Solute: substance in solution that is substance in solution that is dissolved (ex: sugar or salt) dissolved (ex: sugar or salt) Solvent:Solvent: substance in solution substance in solution that does the that does the dissolving (ex: water) dissolving (ex: water)

9. b. Examples:

10. Isotonic 97% H 2 O Diagram Where is the most water? Which way does water go? Result? Big words Examples 97% H 2 O Same Inside and outside Even, same concentration overall “dynamic equilibrium” “homeostasis: - stable internal.] environ. contact lens solution, saline solution

11. Hypotonic Diagram Where is the most water? Which way does water go? Result? Big words Examples 92% H 2 O 97% H 2 O Outside Inside Burst, get bigger; firm “plasmoptysis”- to burst; “turgid”- get firm (PLANTS); “turgor pressure” (PLANTS):pressure inside plant cells to help stand upriight Distilled water; Contractile Vacuoles- organelle that soaks up and pumps out water

12. Paramecium

13. Hypertonic Diagram Where is the most water? Which way does water go? Result? Big words Examples 97% H 2 O 80% H 2 O Inside Outside Smaller, shrink, go limp “plasmolysis”- to wilt, shrivel, loss of pressure; “flaccid”- go limp (PLANTS) Candy, sugar, salt on bushes/grass, gargle with salt water

14. Hypertonic

15. 3. Facilitated Diffusion a. Definition: uses transport proteins to help certain molecules pass through membrane uses transport proteins to help certain molecules pass through membrane b. Ex: Alcohol, H 2 O, small lipids Alcohol, H 2 O, small lipids Allows in bigger molecules Allows in bigger molecules No energy required! No energy required! Fast & specific, high to low concentrations

16. IV. Active transport A. Definition: movement of molecules across a movement of molecules across a membrane requiring energy; from low to membrane requiring energy; from low to high concentration! high concentration! B. Why?: to maintain a certain internal to maintain a certain internal environment; transports environment; transports large molecules in or out large molecules in or out of cell of cell

17. H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O The water from soil moves into roots from HIGH to LOW. But then eventually, the roots will have more water. To prevent the water from going back out, the tree uses ACTIVE TRANSPORT to keep pumping more water in.

18. Ex: Ex: Na + /K + Pump Na + /K + Pump - active transport moves 3 Na+ out of cell and - active transport moves 3 Na+ out of cell and 2 K + into cell 2 K + into cell 2 K+ 3 Na +

19. C. Other Types: “ endocytosis ” & “ exocytosis ” “ endocytosis ” & “ exocytosis ” 1. “ Exocytosis ” a.Definition: removal of large amounts of materials/products Vesicle fuses with membrane, forcing out contents

20. 2. Endocytosis a. Definition: process of taking in a. Definition: process of taking in materials by materials by infoldings of cell membranes infoldings of cell membranes Pocket breaks and forms vesicle in cellPocket breaks and forms vesicle in cell Large food & moleculesLarge food & molecules

21. b. Examples: b. Examples: Phagocytosis: extensions of cytoplasm surround/engulf large particles/food extensions of cytoplasm surround/engulf large particles/food (Seen in macrophages, amoeba) (Seen in macrophages, amoeba)

23. V. Concentration Gradient A. Explanation: measurement of how the concentration of measurement of how the concentration of something changes from one place to another something changes from one place to another B. Passive Transport: molecules go DOWN concentration gradient from molecules go DOWN concentration gradient from HIGH to LOW concentration HIGH to LOW concentration C. Active Transport: molecule go UP concentration gradient from LOW molecule go UP concentration gradient from LOW to HIGH concentration to HIGH concentration