1 / 36

Cell (Plasma) Membrane

Cell (Plasma) Membrane. What is it made of? Why is this a good material for a cell membrane? . Cell Membrane. Phospholipid bilayer Hydrophilic head Hydrophobic tail. Cell Membrane . Homeostasis Steady state maintained by the body Selectively Permeable

cyma
Download Presentation

Cell (Plasma) Membrane

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Cell (Plasma) Membrane What is it made of? Why is this a good material for a cell membrane?

  2. Cell Membrane • Phospholipid bilayer • Hydrophilic head • Hydrophobic tail

  3. Cell Membrane • Homeostasis • Steady state maintained by the body • Selectively Permeable • Regulates what can come in and out of the cell

  4. Selectively Permeable (6.3) Breathing CAN Small Nonpolar • (O2) • (CO2) • WATER CANNOT • Large (glucose) • Polar ( exception is water because its so small) • Ion (charged)

  5. Proteins in the Cell Membrane • “Fluid Mosaic Model” • Many proteins will help transport molecules across the membrane • Proteins drift freely

  6. Membrane Proteins Embedded • Transport Proteins • Cell Recognition Proteins- sugars hang off proteins • Receptors Proteins- receive signals • Enzymes- proteins that make reactions happen

  7. Cell Recognition Proteins • Sugars hang off of proteins in the cell membrane • Give us different blood types

  8. Receptor Protein Receptor Protein-is a cell membrane protein that receives a signal

  9. Transport

  10. Passive Transport: Diffusion • Diffusion • The movement of particles HIGH concentration to LOW concentration Why? • Molecules are always in random motion Ex. Perfume, food coloring, tea bag

  11. Equilibrium- particles equally spread out

  12. Osmosis Water ONLY! • Diffusion of water from HIGH to LOW concentration Solute: Substance in solution that is dissolved (ex. Sugar or Salt) Solvent: Substance in solution that does the dissolving ( ex. Water)

  13. TONICITY Hypotonic Environment Hypertonic Environment Isotonic Environment

  14. 97% H20 97% H2O 97% H2O Isotonic Same Inside and outside Even, same concentration overall “dynamic equilibrium”“homeostasis contact lens solution, Gatorade

  15. Hypotonic 92 % H20 97% H2O Outside Inside Burst, get bigger; firm “cytolysis”- to burst; “turgid”- get firm; “turgor pressure” :pressure inside plant cells to help stand upright - Distilled water ( 100% Water) - Plants standing upright

  16. Hypertonic 97% H20 80% Water Inside Outside Smaller, shrink, go limp “plasmolysis”- to wilt, shrivel, loss of pressure; “flaccid”- go limp

  17. Hypertonic Red Blood Cells

  18. Check Yourself Is the lettuce in a hypertonic isotonic hypotonic environment and why?? Poll

  19. Passive Transport: Facilitated Diffusion Facilitated Diffusion • diffusion across a membrane through transport proteins Ex. sugars, ions , alcohol NO ENERGY: From HIGH to LOW concentration

  20. Active Transport • Movement of molecules across a membrane require energy • From LOW to HIGH concentrations! • Why? • To maintain a certain internal environment: • 1. Sodium Potassium Pump

  21. Active Transport • Exocytosis & Endocytosis • 1. Exocytosis • Removal of materials • Vesicle fuses with membrane, forcing contents out

  22. Active Transport • 2. Endocytosis • process of taking in materials by infolding of the cell membrane • Pocket breaks and forms a vesicle in the cell • Ex. • Pinocytosis: take in fluid • Phagocytosis: Large particle/food • Amoeba

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

  24. Review Video of Transport

  25. Elodea Plasmolysis

  26. http://www.youtube.com/watch?v=2Th0PuORsWY

  27. “Egg”citing “Eggs”perimentCell membrane

  28. Egg Lab: Osmosis

  29. Why does a plant like hypotonic but an animal does not? • http://www.phschool.com/science/biology_place/labbench/lab1/watpot.html

More Related