MOVEMENT OF MATERIAL THROUGH THE CELL MEMBRANE

1. MOVEMENT OF MATERIAL THROUGH THE CELL MEMBRANE GPS: EXPLAIN THE ROLE OF CELL ORGANELLES IN BOTH PROKARYOTES AND EUKARYOTES IN MAINTAINING HOMEOSTASIS

2. I CAN STATEMENT FOR TODAY!!! • I CAN TELL HOW THE CELL MEMBRANE WORKS TO KEEP HOMEOSTASIS IN ALL ORGANISMS..

3. HOMEOSTASIS • THE REGULATION AND MAINTAINING A CONSTANT INTERNAL CONDITION IN AN ORGANISM. EXAMPLE 3 EXAMPLE 1 EXAMPLE 2

4. CELL MEMBRANEREGULATES HOMEOSTASIS • Thin, flexible barrier around the cell that controls what enters and leaves the cell. • The CELL MEMBRANE IS A LIPID BILAYER.

5. CELL MEMBRANE IS A LIPID BILAYERaka phospholipid bilayer

6. The cell membrane is selectively permeable. Some molecules can cross the membrane, other cannot. Materials move across the cell membrane because of concentration differences. CORNSTARCH DEMONSTRATION

7. Cytoplasm of a cell is a solution of many different substances in water. • In solution, molecules move constantly • Solute – substance that is dissolved • Solvent – substance (usually H2O) that the solute is dissolved in

8. Passive Transport • Passive transport does not require energy input from a cell and moves molecules from High to Lowconcentration • The three types of passive transport are • Diffusion • Osmosis • Facilitated Diffusion

9. DIFFUSION • Movement of a fluid or gas from an area of high concentration to an area of low concentration.

10. Equilibrium is reached when the concentration of the solute is the same throughout a solution

11. FACILITATED DIFFUSION • DIFFUSION OF A SUBSTANCE ACROSS THE CELL MEMBRANE THROUGH CARRIER PROTEINS. • PROTEIN CHANNELS • PROTEIN MOLECULED EMBEDDED IN THE CELL MEMBRANE

12. IN FACILITATED DIFFUSION, MOLECULES THAT ARE TOO LARGE ARE “HELPED” BY A PROTEIN CHANNEL TO MOVE FROM HIGH TO LOW CONCENTRATION. • NO ENERGY IS USED • LET’S WATCH!!!!!

13. OSMOSIS • The diffusion of water through a selectively permeable membrane • In Osmosis, the 3 solutions (one on each side of the membrane) are compared as follows:

14. Isotonic – when the solutions on both sides of the membrane has the same concentrations of solutes. (equilibrium/homeostasis) • Hypertonic– the solution outside the membrane has a higher concentration of solutes than inside the cell • Hypotonic – the solution outside the membrane has lower concentration of solutes than inside the cell.

15. Water molecules will move back and forth across the membrane, but remain equal "ISO" means the same

16. COMPLETE TABLE The OSMOSIS TABLE..

17. HYPERTONIC SOLUTION

18. HYPERTONIC SOLUTION PLANT CELL

19. HYPERTONIC SOLUTION ANIMAL CELL

20. HYPOTONIC SOLUTION

21. HYPOTONIC SOLUTION PLANT CELL

22. HYPOTONIC SOLUTION ANIMAL CELL.

23. ISOTONIC SOLUTION

27. BACK-UP- FACILITATED DIFFUSION • LET’S • WATCH!!!

28. BACK-UP- FACILITATED DIFFUSION • LET’S • WATCH!!!

29. ACTIVE TRANSPORT • Material movesacross the cellmembrane against the concentration gradient • from an area of low concentration to an area of high concentration • Energy input is required

30. Active transport is powered by chemical energy (ATP). • Active transport occurs through transport protein pumps. • Cells use active transport to maintain homeostasis. • Sodium/Potassium pump – pumps IONS against the concentration gradient. LET’S WATCH!!!

32. Endocytosis – active transport process by which a cell surrounds and takes in materials from its environment. • The pocket breaks off inside the cell and forms a vacuole

33. Exocytosis – the removal of large amounts of material from a cell. • The membrane of the vacuole surrounding the material fuses with the cell membrane, expelling the contents from the cell • LET’S • WATCH!!!

34. Back-Up • Endocytosis and Exocytosis