Topic 2.4: Cell Membranes

1. Topic 2.4: Cell Membranes

2. Functions of a plasma membrane:

3. http://www.youtube.com/watch?v=00PPPt7EJqo

5. The Fluid Mosaic Model What is a fluid? What is a Mosaic? What is a model? The fluid mosaic model tells us: The phospholipids have freedom of movement in the horizontal plane: they can move around reach other, and can flow with pressure, yet they do not break.

6. The Fluid Mosaic Model What is a fluid? What is a Mosaic? What is a model? The individual phospholipids are attached to each other by: The phospholipids have freedom of movement in the horizontal plane: they can move around reach other, and can flow with pressure, yet they do not break.

7. http://www.youtube.com/watch?v=hepoJgGJtNc Why doesn’t this egg cell rupture when the pipette drills in through the membrane?

8. What are the name and functions of these parts of the plasma membrane?

9. Click to start cell signaling animation http://www.youtube.com/watch?v=U6uHotlXvPo

10. Click to start animation http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP1101

11. The phospholipid bilayer is selectively permeable Molecular movement:

13. Diffusion is: Diffusion can occur through a partially or selectively permeable membrane.

14. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/

15. Try the lab bench for Diffusion and Osmosis http://www.phschool.com/science/biology_place/labbench/index.html

16. Diffusion is…

17. Explain three factors, other than temperature that affect the rate of diffusion of a solute across a membrane

18. Adaptations in biology: Maintaining a large gradient Source Keep adding molecules to the ‘high’ side of the gradient …and removing them from the ‘low’ side. Sink

19. Adaptations in biology: Maximizing surface area for absorption

20. Adaptations in biology: Reducing the length of diffusion path: http://www.masterfile.com/stock-photography/image/861-03336305/A-typical-mitochondrion-from-the-pancreas-showing-the-cristae-matrix-and-matrix-granules.--TEM-X45000

21. Facilitated diffusion is the passive net movement of particles from regions of high concentration to low concentration, through a selectively permeable membrane, facilitated by carrier proteins.

22. Facilitated diffusion is the passive net movement of particles from regions of high concentration to low concentration, through a selectively permeable membrane, facilitated by carrier proteins. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/

23. Osmosis is the passive net movement of water molecules from regions of low solute concentration to high solute concentration through a partially selectively permeable membrane.

24. Osmosis is the passive net movement of water molecules from regions of low solute concentration to high solute concentration through a partially selectively permeable membrane. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/

25. Can you explain why the water levels changed? More water Less water http://2six.edu.glogster.com/transport-in-living-things-iii/

26. Does this explanation help? http://www.youtube.com/watch?v=sdiJtDRJQEc

27. Water moves by osmosis from an area of low solute concentration (more water) to high solute concentration (less water). The solute particles cannot move to balance the concentration because they are too large to fit through the pores of the selectively permeable membrane. http://2six.edu.glogster.com/transport-in-living-things-iii/

28. Compare diffusion and osmosis Similar: Different:

29. Try out this fun tutorial on Diffusion and Osmosis!! http://education.uoit.ca/lordec/ID_LORDEC/diffusion_osmosis/garib_diffusion_osmosis.swf

30. Analyze the information in this graph Explain the significance of the point labeled in red Explain the blue line Deduce the experimental method used to generate this graph. Discuss how the dependent variable was recorded and calculated. How would the researcher ensure that data were sufficient, relevant, and reliable. Discuss the variables that needed to be controlled in the investigation. Whatcould be the impact of each of them? How could they be controlled?

31. Osmosis: finding the concentration of salt in potato cells

32. Active transport uses energy, in the form of ATP, to move molecules against a concentration gradient, using membrane protein pumps.

33. Try out this fun tutorial on Membrane Transport!! http://programs.northlandcollege.edu/biology/Biology1111/animations/active1.swf

34. Active transport continued… Protein pumps: http://plantcellbiology.masters.grkraj.org/html/Plant_Cellular_Physiology4-Absorption_Of_Mineral_Nutrients.htm

35. http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio03.swf::Sodium-Potassium%20Exchange%20Pumphttp://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio03.swf::Sodium-Potassium%20Exchange%20Pump

36. ATP – Adenosine Tri-Phosphate

37. Exocytosis Vs. Endocytosis Exo – Exit Cytosis – cell Sis - Process Endo – Enter Cytosis – cell Sis - process http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio02.swf::Endocytosis%20and%20Exocytosis

38. Vesicle transport: Exocytosis of protein molecules using Golgi apparatus http://www.uic.edu/classes/bios/bios100/lectures/cells.htm

39. http://www.youtube.com/watch?v=bD4z27ASN1M

40. Vesicle transport resources: http://learn.genetics.utah.edu/content/begin/cells/vesicles/ When the vesicle reaches the cell membrane it fuses with the membrane and release its contents. Try the link to see some videos on how vesicles move in a cell. budding vesicle fusing Contents released

41. Acknowledgements/Work Cited: I’d like to thank Mr. Stephen Taylor for the ability to use and adapt his material and resources, and for his generous support. 1. Taylor, Stephen.2.4 Membranes (presentation). i-Biology. [Online] July 2012. http://i-biology.net/ibdpbio/02-cells/eukaryotes/