Cell Membrane Transport Notes

1. Cell Membrane Transport Notes April 1, 2014

2. I.) Types of Cell Membrane Transport • There are 2 types of cell membrane transport: • Passive Transport • Things flow from High to low • Active Transport • Things flow from Low to high

3. Passive & Active Transport

4. II.) Passive Transport • Diffusion • Definition: The movement of particles from areas of high concentration to low concentration • http://www.indiana.edu/~phys215/lecture/lecnotes/diff.html • http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

5. Equilibrium • Continuous movement of particles, but no change in concentration • When is equilibrium reached when discussing cell membrane transport? • When the concentrations of particles are the same on both sides

6. Facilitated Diffusion • Particles flow from high concentration to low concentration but this time they need the help of proteins to get through the cell membrane.

7. Passive transport (cont.) • Osmosis • The diffusion of water across a selectively permeable membrane • Important in maintaining cell homeostasis • Water flows to side of membrane where the water concentration is lower until equilibrium is reached

8. Osmosis (cont.) • Osmosis is controlled by the amount of solutes on either side of a membrane

9. Remember, this is important, Osmosis deals with what? • The movement of particles • The movement of glucose • The movement of water • The movement of lipids

10. Osmosis – Types of Solutions • When dealing with osmosis, water can either move into the cell or out of it. • We describe the solutions that cells are in as either hypotonic, isotonic, or hypertonic. 90% What are the concentrations? 40%

11. Isotonic Solution • Isotonic solution – Concentration of solute is the same in the cell and the area around the cell.

12. Isotonic solution

13. Hypotonic Solution • Hypotonic Solution – Concentration of solute is lower in the solution than in the cell. • Where is water going to move in order to reach equilibrium (Equal concentrations)? • Inside the cell

14. Hypotonic solutions • Since water moves into the cell the cell can explode • So, Hypotonic solution, low concentration of solute, cell can explode

15. Plant & animal cells in a hypotonic solution

16. Hypertonic Solution • Hypertonic solution – concentration of solute is higher in the solution than in the cell. • Where is water going to move in order to reach equilibrium (Equal concentrations)? • Outside the cell

17. Hypertonic solutions • Since water moves out of the cell the cell will shrink • So, Hypertonic solution, high concentration of solute, cell will shrink

18. Plant & animals cells in a Hypertonic Solution

19. The following diagram demonstrates what type of solution? = solute • Hypotonic • Isotonic • Hypertonic

20. In the following diagram which way is water going to move? = solute • Inside the cell • Outside of the cell • Both 1 and 2

21. The following diagram demonstrates what type of solution? = solute • Hypotonic • Isotonic • Hypertonic

22. In the following diagram which way is water going to move? = solute • Inside the cell • Outside of the cell • Both 1 and 2

23. Active Transport • Molecules move from low concentration to high concentration • Requires energy….why?

24. Other membrane transport activities that require energy • Endocytosis • Engulfing of large particles or liquids from outside the cell

25. 2 types of Endocytosis • Phagocytosis • Engulfing of large particles from outside the cell • Pinocytosis • Engulfing of liquids from outside the cell

26. Other membrane transport activities that require energy • Exocytosis • Release of large particles or liquids from inside the cell Outside the cell Inside the cell

27. This diagram is an example of what membrane transport? • Diffusion • Facilitated diffusion • Endocytosis • Exocytosis

28. This diagram is an example of what membrane transport? • Diffusion • Facilitated diffusion • Endocytosis • Exocytosis