2. We need to understand the basic process of transport across a plasma membrane. We are learning...  That the cell has a semi-permeable membrane  To understand the difference between passive and active transport

3.  Controls what goes in and out of the cell  Cell membrane is composed of different structures: Phospholipid bilayer Protein Channels Carbohydrates Cholesterol  Together these structures make up the Fluid Mosaic Model

6. The cell membrane selects substances to enter and leave the cell (semi-permeable) What is entering?  Water and uncharged molecules (E.g. O 2, CO 2 ) What is leaving?  Water and waste (E.g. Fatty Acids)

7.  Phospholipid Bilayer: holds components of the cell together  Proteins: transport specific substances across membrane and aids in signaling  Cholesterol: keeps fluidity of the cell membrane  Carbohydrates: identifies molecules entering the cell

8. HYDROPHOBIC: WATER HATING HYDROPHILIC: WATER LOVING

9. Substances can be transported across cell membrane in 2 different ways: 1. PASSIVE TRANSPORT  requires no energy  Substances travel from high to low concentration 2. ACTIVE TRANSPORT  requires energy  Substances travel from low to high concentration

10. Movement of molecules from a region of high to low concentration  No energy needed  Stops when the concentration of particles are equal everywhere  EQUILIBRIUM  Small molecules travel across the phospholipid bilayer in this fashion I

12. 1. TEMPERATURE:  Molecules move faster and reach equilibrium quicker 2. CONCENTRATION:  The bigger difference in concentration, the faster the rate of diffusion 3. SIZE OF MOLECULE:  Smaller molecules diffuse faster than large molecules

13. Diffusion with the aid of membrane proteins Proteins are very selective:  Bind to an identified molecule and transport it across the cell membrane (ex. Na + and Cl - Ions)  Energy not needed

14.  The diffusion of water across a selectively permeable membrane  Occurs when water concentrations differ on either side of the cell membrane  Water moves to ensure that the concentration of water is equal on both sides of the cell membrane  EQUILIBRIUM

16. There are three different types of solutions: 1. ISOTONIC SOLUTION 2. HYPERTONIC SOLUTION 3. HYPOTONIC SOLUTION

17. CONDITIONS: equal concentration inside and out WATER MOVEMENT:  water molecules go in and out of the cell at the same rate  No net movement CELL SIZE: stays the same

18. CONDITIONS: The solution has a higher concentration of solute than inside the cell WATER MOVEMENT: Water will move out of the cell CELL SIZE: cells will shrink and shrivel

19. CONDITIONS: The solution has a lower concentration of solute than inside of the cell WATER MOVEMENT: Water will move inside the cell CELL SIZE: expands and swells

22. http://www.northland.cc.mn.us/biology/bi ology1111/animations/passive1.swf http://bcs.whfreeman.com/thelifewire/co ntent/chp05/0502001.html http://biology- animations.blogspot.com/2011/06/cell- membrane-passive-transport.html http://www.teachersdomain.org/asset/tdc 02_int_membraneweb/

23.  Read pages 62-70 Answer questions on:  Page 63 # 10, 11  Page 68 # 13, 14  Page 70 # 16-18  page 71# 1-2, 5-6, 9