1. Active Transport, Diffusion and Osmosis

2. Passive Transport by Diffusion Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.(down the concentration gradient) Diffusion does not refer only to movement across a membrane.

4. How Diffusion Works http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_diffusion_works.htmlhttp://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_diffusion_works.html

5. Passive Transport by Osmosis Osmosis is the movement of water across a biological membrane. Water molecules move from an area of low concentration solute (hypotonic) to an area of high concentration (hypertonic) Water moves because the membrane is impermeable to the solute

6. Affect of Osmosis http://www.etomica.org/app/modules/sites/Osmosis_old/Background1.html

7. Affect of Osmosis http://en.wikipedia.org/wiki/User:Reo_On/Passive_transport

9. How Osmosis works http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_osmosis_works.htmlhttp://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_osmosis_works.html

10. Passive transport by Facilitated Diffusion Molecules can enter a cell by diffusion through a specific channel proteins or carrier proteins embedded in the membrane This process mediated by a membrane protein is called facilitated diffusion Molecules move down the concentration gradient

11. Channel Proteins Form highly specific channel through the cell membrane Permit the passage of ions or polar molecules Some channel proteins remain open all the time, others have gates that can be opened or closed to allow or prevent the passage of particles

12. http://www.biologycorner.com/APbiology/cellular/(notes)cell_membrane.html

13. Carrier Proteins Bind to specific molecules, transport them across the membrane and release them Carrier molecules change shape while transporting molecules Usually transport ions or small polar molecules but can also transport amino acids and glucose Have a lower rate of diffusion than channel proteins

14. Channel and Carrier Proteins http://www.ncbi.nlm.nih.gov/books/NBK9928/

15. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_facilitated_diffu sion_works.htmlhttp://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_facilitated_diffu sion_works.html

16. Active Transport Active transport is the movement of ions, molecules or minerals from an area of low concentration to an area of high concentration(against the concentration gradient) This requires energy in the form of ATP

17. Primary Active Transport Uses ATP directly to move molecules or ions from one side of the membrane to the other Ion pumps are carrier proteins that pump ions against the concentration gradient The sodium-potassium pump pumps Na + out of the cell and K + ions into the cell

18. http://saddlebackphysio.blogspot.com/2010/09/membrane-transportjust-passin-through.html

19. How the Sodium-Potassium pump works http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__how_the_sodium_po tassium_pump_works.html

20. Secondary Active Transport As an ion pump functions, a difference in charge, or electrical potential, builds up across the membrane One side of the membrane gains a more positive or negative charge compared to the other side due to the accumulation of positive or negative ions

21. Secondary Active Transport The combination of concentration gradient and electrical potential is called an electrochemical gradient This gradient stores potential energy that can be used by the cell This energy is used by another protein to transport other molecules across a membrane

22. Electrochemical Gradient http://bioap.wikispaces.com/Ch+7+Collaboration+2010

23. http://www.cetbiology.com/support/biology-photographs.html

24. Membrane-Assisted Transport Macromolecules are too large to cross the cell membrane through a channel or by means of a carrier protein Cells form vesicles to surround incoming or outgoing material and move it across the cell membrane Membrane-assisted transport requires energy

25. Endocytosis The process where a cell engulfs material by folding the cell membrane around it and then pinching it off to form a vesicle inside There are three methods: –Pinocytosis –Phagocytosis –Receptor-mediated endocytosis

26. Receptor-mediated Endocytosis http://www.yellowtang.org/cells.php

27. Pinocytosis http://www.yellowtang.org/cells.php

28. Phagocytosis http://www.yellowtang.org/cells.php

29. Exocytosis Macromolecules and other large particles leave a cell by exocytosis Vesicles that contain cell products to be released or waste products to be excreted fuse with the cell membrane and empty their contents into the extracellular environment

30. http://www.linkpublishing.com/video-transport.htm

31. Phagocytosis http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__phagocytosis.htmlhttp://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__phagocytosis.html