Activating Prior Knowledge

1. What is an egg? A chicken egg to be more precise… Egg Osmosis Soak a chicken egg in vinegar to Remove the cell, and Denature the outer protein Then you have a big cell to experiment with! View and Interpret Egg Osmosis Video Activating Prior Knowledge

2. explain the impact of water on life processes (i.e., osmosis, diffusion, SB1d). explain the role of the cell membrane, in maintaining homeostasis (transporting materials in/out of cell). Use vocabulary: hypertonic, hypotonic, isotonic Passive Transport: diffusion, osmosis, facilitated diffusion Active Transport: sodium/potassium pump and endo/exocytosis After this lesson, you should be able to

3. Solvent – the larger material {liquid} that dissolves the solute Water is considered the “universal” solvent Solute – smaller substance that is dissolved by the solvent. Ex. tea & sugar Solution – Complete mixture of solute and solvent Ex. Sweet tea Solution Review

4. Quick Check! I mixed Kool-Aid powder in water. Describe the mixture using the terms: solute, solvent, and solution.

5. Words to know: Hypertonic More solute Hyper means higher {more concentrated} Isotonic Solution has achieved equilibrium Hypotonic Less solute Hypo means lower less concentrated Equilibrium achieving balance or equal

7. Equal volume of cold and warm water, each in separate clear cups What will happen if we drop equal amounts of food coloring in each? Let’s try it and observe. youtube Explain what you see. Lead discussion to develop diffusion definition including Movement of a substance Random molecular motion Kinetic energy Concentration gradient equilibrium Diffusion Demonstration

8. Movement of substances from high concentration to low concentration Movement “down a concentration gradient” Due in part to random, rapid motion of molecules. Net Movement Equilibrium State Simple Diffusion. Roles in the Body Factors that Affect Rate: permeability of membrane Size of gradient temperature Diffusion

10. Passive Transport • Movement of materials in & out of the cell without {NO} Energy Hypertonic High Low Hypertonic hypotonic Hypotonic

11. Passive O2, CO2, H2O across cell membrane Smells spreading Movement of any molecules from a high concentration to a low concentration. Diffusion

13. Osmosis Diffusion of water across a semi- permeable membrane

14. Diffusion of water through a selectively permeable membrane. Movement of water from “less salty” to “more salty” side of membrane from low solute concentration to high solute concentration. from high water concentration to low water concentration. Hypertonic Hypotonic Isotonic In everyday life: Preservation of food Eating of salty or sugary foods Salt on a slug contractile vacuoles turgur pressure in plants Osmosis

15. Diffusion and Osmosis Experiment

16. OSMOSIS DEMONSTRATION(DIALYSIS BAGS)

17. Interpret this experiment!

18. OSMOSIS IN PLANT CELLSWhat’s happening to the water in the cell? HYPOTONIC SOLUTION= NORMAL TURGOR PRESSURE HYPERTONIC SOLUTION= PLASMOLYSIS

19. OSMOSIS IN PLANT CELLS (Elodea) Plasmolyzed cells

20. Solution Concentrations • Isotonic Solution • When a cell is in a solution that has the same concentration of water and solutes • Hypotonic Solution • A cell is in a solution that has a lower concentration of solute • Hypertonic Solution • A cell is in a solution that has a higher concentration of solute outside of the cell

21. Quick Check Knowing what we know about osmosis, what would happen to the water in a cell in: 1. an isotonic solution? 2. a hypotonic solution? 3. a hypertonic solution?

22. Passive Hyper to Hypo Diffusion of water molecules across a membrane. Net movement of water toward high solute (hypertonic) side of membrane Osmosis

23. Osmosis and Animal Cells NO CHANGE WILL LYSE CRENATION

24. Facilitated Diffusion • Passive • Diffusion that uses channel proteins • Hyper to Hypo • Large molecules like glucose

25. Movement from high concentration to low concentration through carrier proteins. Used to move ionic or large substances into or out of cells Passive process Carrier proteins are specific (will only move one substance) Important for moving sugars and amino acids into cells Facilitated Diffusion

26. Active Transport Low to High • Movement of materials in & out cell WITH energy High Low

27. Quick Check! What is the main difference between active and passive transport?

28. Ion or Solute pump • Active • Protein channel • hypotonic to hypertonic • Ex. Na+ K + pump • To “pump” means it uses energy (ATP)

29. Movement of substances against a concentration gradient. From low concentration to high concentration. requires energy pumping a substance ATP must be hydrolyzed to fuel this process Sodium-Potassium Pump Pumps sodium out of cells and potassium into cells. Important for the functioning of nerves and muscles. Pump is a membrane protein and an enzyme--ATPase. Active Transport

31. Sodium-Potassium Pump (this allows for nerve function!) 3 Na+ pumped in for every 2 K+ pumped out; creates a membrane potential

32. Moving the “Big Stuff” Exocytosis- moving things out. Molecules are moved out of the cell by vesicles that fuse with the plasma membrane. This is how many hormones are secreted and how nerve cells communicate with one another.

33. Pinocytosis • Cell forms an invagination • Materials dissolve in water to be brought into cell • Called “Cell Drinking”

34. Endocytosis – Phagocytosis Used to engulf large particles such as food, bacteria, etc. into vesicles Called “Cell Eating”

35. Three Forms of Transport Across the Membrane

36. ANOTHER ONLINE TUTORIAL Cellular TransportOn-Line Tutorial(11 slides with animated molecules moving across cell membrane; includes quiz questions along the way)

37. Closing Challenge – Create a “Cell Transport Concept Map” with these words: Active TransportATP Cell TransportConcentration GradientDiffusionEndocytosisExocytosisFacilitated Diffusion Passive TransportOsmosisO2, CO2, H2O glucoseNa+ & K+ ions