THIS SLIDE IS PRESENTED TO YOU BY<br />HAMZA RASHEED<br />&<br />MUHAMMED HAFEEZ (ADMIN OF HELP IN STUDIES ON FACEBOOK)<br...
Learning Objectives<br />To know about the structure of cell membrane.<br />To know about diffusion and diffusion through ...
Lipid Barrier of the Cell Membrane and Cell Membrane Transport Proteins<br />
Diffusion<br />Random molecular movement of substances molecule by molecule, either through intermolecular spaces in the m...
Active transport<br />Movement of ions or other substances across the membrane in combination with a carrier protein in su...
Diffusion<br />Two types of diffusion takes place across cell membrane:-<br />1-Simple diffusion<br />2-Facilitated diffus...
Simple diffusion<br />It means the kinetic movement of molecules or ions that occurs through a membrane opening or through...
Pathways of simple diffusion<br /><ul><li>Through the interstices of lipid bilayer in case of lipid bilayer substances.
Through watery channels that penetrate all the way through some large transport proteins. </li></li></ul><li>Determinants ...
Velocity of kinetic motion
Number of opening in membrane
Size of the openings</li></li></ul><li>Facilitated diffusion<br />It requires interaction of a carrier protein.<br />Ions ...
Diffusion of Lipid soluble substances<br /><ul><li>It is directly proportional to the lipid solubility of the substance.
High lipid soluble substances:-
Oxygen
Nitrogen
CO2
Alcohol</li></li></ul><li>Diffusion of Lipid insoluble substances <br />Water and other lipid insoluble molecules penetrat...
Diffusion through Protein channels<br />It has two imp. characteristics:-<br /><ul><li>Selective permeability
Gating of proteins channels</li></li></ul><li>Selective permeability<br />It depends on following characteristics of chann...
Shape
Nature of electrical charge
Chemical bonds on inside surface</li></li></ul><li>Na channel<br /><ul><li>0.3 by 0.5 nm in diameter
Inner surface  are strongly negatively charged.
These –ive charges pull small dehydrated Na ions into channel.
Once inside the channel , go in either direction.</li></li></ul><li>
K channels<br />Selective for K ions.<br />0.3 by 0.3 nm in diameter.<br />Not negatively charged.<br />Chemical bonds are...
Upcoming SlideShare
Loading in …5
×

Cell Part 1

397 views

Published on

PHYSIOLOGY CELL
PART 1

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
397
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
7
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Cell Part 1

  1. 1. THIS SLIDE IS PRESENTED TO YOU BY<br />HAMZA RASHEED<br />&<br />MUHAMMED HAFEEZ (ADMIN OF HELP IN STUDIES ON FACEBOOK)<br />http://www.facebook.com/group.php?v=wall&gid=319795502526<br />PLEASE STOP PIRACY & STEALING PEOPLE WORK,<br />AND GET a LIFE.<br />PEACE<br />THANKS<br />
  2. 2.
  3. 3. Learning Objectives<br />To know about the structure of cell membrane.<br />To know about diffusion and diffusion through cell membrane.<br />
  4. 4.
  5. 5.
  6. 6. Lipid Barrier of the Cell Membrane and Cell Membrane Transport Proteins<br />
  7. 7.
  8. 8. Diffusion<br />Random molecular movement of substances molecule by molecule, either through intermolecular spaces in the membrane or in combination with a carrier protein.<br />
  9. 9. Active transport<br />Movement of ions or other substances across the membrane in combination with a carrier protein in such a way that the carrier protein causes the substance to move against an energy gradient.<br />
  10. 10. Diffusion<br />Two types of diffusion takes place across cell membrane:-<br />1-Simple diffusion<br />2-Facilitated diffusion<br />
  11. 11.
  12. 12. Simple diffusion<br />It means the kinetic movement of molecules or ions that occurs through a membrane opening or through intermolecular spaces without any interaction with carrier proteins in the membrane.<br />
  13. 13. Pathways of simple diffusion<br /><ul><li>Through the interstices of lipid bilayer in case of lipid bilayer substances.
  14. 14. Through watery channels that penetrate all the way through some large transport proteins. </li></li></ul><li>Determinants of rate of diffusion <br /><ul><li>Amount of substance available
  15. 15. Velocity of kinetic motion
  16. 16. Number of opening in membrane
  17. 17. Size of the openings</li></li></ul><li>Facilitated diffusion<br />It requires interaction of a carrier protein.<br />Ions bind chemically with the proteins. <br />
  18. 18. Diffusion of Lipid soluble substances<br /><ul><li>It is directly proportional to the lipid solubility of the substance.
  19. 19. High lipid soluble substances:-
  20. 20. Oxygen
  21. 21. Nitrogen
  22. 22. CO2
  23. 23. Alcohol</li></li></ul><li>Diffusion of Lipid insoluble substances <br />Water and other lipid insoluble molecules penetrates through channel proteins.<br />Their diffusion depends on their size.<br />E.g Urea- 20% greater diameter than water.1000 times less penetration.<br />
  24. 24. Diffusion through Protein channels<br />It has two imp. characteristics:-<br /><ul><li>Selective permeability
  25. 25. Gating of proteins channels</li></li></ul><li>Selective permeability<br />It depends on following characteristics of channel:-<br /><ul><li>Diameter
  26. 26. Shape
  27. 27. Nature of electrical charge
  28. 28. Chemical bonds on inside surface</li></li></ul><li>Na channel<br /><ul><li>0.3 by 0.5 nm in diameter
  29. 29. Inner surface are strongly negatively charged.
  30. 30. These –ive charges pull small dehydrated Na ions into channel.
  31. 31. Once inside the channel , go in either direction.</li></li></ul><li>
  32. 32. K channels<br />Selective for K ions.<br />0.3 by 0.3 nm in diameter.<br />Not negatively charged.<br />Chemical bonds are different.<br />
  33. 33.
  34. 34. Gating of Protein channels<br /><ul><li>Two principal ways:-
  35. 35. Voltage gating
  36. 36. Chemical (Ligand) gating</li></li></ul><li>
  37. 37. Voltage Gating<br />When there is strong negative charge inside of cell membrane, it causes Na gates to remain tightly closed.<br />When inside negativity is lost, these gates would open suddenly and Na pores inward.<br />
  38. 38.
  39. 39. K gates are on intracellular ends of K channels and open when inside of CM becomes positively charged.<br />Their opening is partly responsible for terminating action potential.<br />
  40. 40. Chemical Gating<br />Some protein channel gates open by binding of chemical substances with the protein.<br />It causes conformational change that opens or closes the gates.<br />This is chemical or ligand gating.<br />
  41. 41. Example is the role of Ach in acetylcholine channels.<br />Ach opens the channel and provide -ivity inside that allows uncharged molecules or positive ions to pass through.<br />
  42. 42. Important for transmission of nerve signal from one nerve cell to another or from nerve cell to muscle cell.<br />

×