1. Cellular Transport

2. Introduction to Cell Transport Cell transport= moving materials in and out of a cell All living cells need to be able to: – Take in oxygen and nutrients – Get rid of wastes The cell membrane separates the inside of the cell from the outside. – It allows some things to enter and blocks other things

3. Cell Membrane Structure Phospholipid Bilayer- double layer of phospholipids enclosing the cell 1.Bilayer: Exterior and interior surface: heads Between: tails

4. Phospholipid Bilayer

5. Membrane Proteins Membrane proteins can be used to: – transport materials thru the membrane – serve as chemical signals or receptors of chemical signals. Membranes also can contain cholesterol (animal cells) and glycoproteins.

6. Fluid Mosaic Model Describes the cell membrane as a fluid rather than a solid. – Phospholipids and some proteins are able to move – This is able to change its shape and form. http://www.youtube.com/watch?v=Qqsf_UJcf Bc http://www.youtube.com/watch?v=Qqsf_UJcf Bc

7. Selective Permeability The cell membrane regulates what can pass in or out of the cell. – this maintains a stable internal environment (homeostasis) – Factors that determine a substances’ ability to pass thru the membrane: Size Shape Composition Polarity (polar or nonpolar) Charge (positive or negative)

8. Solutions Solution= combination of solute and solvent – Solute= Substance being dissolved – Solvent= thing substance is dissolved in Universal solvent= water *Solute dissolves in the solvent Example: Saltwater

9. Concentration Amount of solute compared to the amount of solvent – Low concentration of solute Lesser amount of solute dissolved – High concentration of solute Higher amount of solute dissolved

10. Particle Movement Brownian motion- constant random motion of all particles.

11. Passive Transport Movement that does not require energy – No energy needed from the cell Types: – Diffusion – Facilitated Diffusion – Osmosis

12. Diffusion Movement from high to low concentration. – Concentration Gradient= A difference in concentration (A concentration gradient is when there is a difference in concentration within a system) – Particles will move until concentration is equal throughout the system (Dynamic Equilibrium)

13. Diffusion Animation

15. Facilitated Diffusion Diffusion of particles with the help of membrane proteins. 1.Carrier proteins change shape to move large molecules thru the lipid bilayer.

16. Facilitated diffusion of Glucose

17. 2.Ion channels – A tube for dissolved ions to pass thru the lipid bilayer. Ex. Na + ion channel

18. Osmosis The diffusion of water. – High to low concentration of water – Water will move in the opposite direction of the solute Types of solutions: 1. Hypertonic solution- lower concentration of water outside the cell. water will rush out of the cell – Causes wilting in plant cells.

19. Hypotonic Solution Solution with a higher concentration of water than the cell. – water will move into the cell causing it to swell Can cause bursting of animal cells

20. Isotonic solution Equal concentration of water in the solution and the cell. – net movement of water and solute is equal – cell is in dynamic equilibrium w/ the solution http://www.youtube.com/watch?v=7-QJ- UUX0iY http://www.youtube.com/watch?v=7-QJ- UUX0iY

21. Osmosis in plant cells

22. Osmosis of red blood cells

23. Osmotic pressure Which way will the water move?

24. How Cells Deal with Osmosis How do cells like paramecium that live in water, not blow up? – Contractile vacuoles – organelles that remove water from the cell.

25. Questions 1.Can things always diffuse in and out of the cell when they want to? – In your answer, use the words: selectively permeable passive transport. 1.Give a short description (in your own words) of the three types of passive transport.

26. Active Transport Movement of substances that requires cell energy. – Movement from low to high concentration – Necessary to maintain homeostasis

27. Proteins Pumps Proteins that force particles to move –E–Energy is used to change the shape of the protein. –e–ex. Na+/K+ ion pump Uses energy to keep a high concentration of Na+ outside the cell and K+ inside the cell. http://www.youtube.com/watch?v=P- imDC1txWw

28. Na + /K + ion pump

29. Endocytosis Ingesting large particles or large amounts of solution. – membrane pinches off around material creating a vacuole – Types Pinocytosis- ingesting large amounts of fluid or solutes. Phagocytosis- ingesting large particles or whole cells. – ex. White blood cells, Ameoba

30. Exocytosis Release of large particles from the cell – excretory vesicles fuse w/ the cell membrane releasing the material outside the cell. http://www.youtube.com/watch?v=DuDmvlb pjHQ http://www.youtube.com/watch?v=DuDmvlb pjHQ

31. Endocytosis and Exocytosis

32. Endocytosis vs. Exocytosis Which is endocytosis? Exocytosis?