1. Types Cell transport across the cell membrane

2. Cell Membrane structure
Phospholipid Bilayer
Proteins (peripheral and integral)
Carbohydrates

3. Functions of the cell membrane
Protective barrier that regulates transport in & out of cell (selectively permeable)
Provide anchoring sites for filaments of cytoskeleton
Contains the cytoplasm (fluid in cell)
Maintain homeostasis (balance between inside and out)

4. Fluid Mosaic Model
FLUID- because individual phospholipids and proteins can move around freely within the layer, like it’s a liquid. MOSAIC- because of the pattern produced by the scattered protein molecules when the membrane is viewed from above.

5. Water and the membrane Polar heads are hydrophilic “water loving”
Nonpolar tails are hydrophobic “water fearing”

6. How things enter and leave the cell
3 different ways
Pass directly through the membrane
Through a transport/ channel protein
Transport Vesicles

7. Types of transport Passive Transport-(no energy required) Diffusion
Osmosis
Facilitated Diffusion
Active Transport (energy required)
Endocytosis
Ectocytosis
Sodium /Potassium Pump

8. Diffusion Requires no energy and is a passive movement.
Molecules move from an area of high concentration to an area of low concentration.
Examples: Oxygen and water going in, carbon dioxide going out.

9. Diffusion of liquids

10. Diffusion Animations
hill.com/sites/ /student_view0/chapter2/animation__how_diffusion _works.html

11. Osmosis Diffusion of WATER across a membrane
Moves from HIGH water potential (low solute) to LOW water potential (high solute)
No Energy Required

12. Isotonic solutions Hypotonic solution Hypertonic solution
Osmosis conditions
Isotonic solutions
When the amount of solutes is equal inside and outside of cell (cell will stay the same)
Hypotonic solution
When solutes outside are lower than inside cell (cell will swell) * more water outside
Hypertonic solution
When solutes outside are higher than inside cell (cell will shrink) * more water inside cell

13. Cell shrivel and bursting
If a cell has too much water inside, it will burst open or lyse. (cytolysis)
If a cell has more water outside the cell, it will shrivel. (plasmolysis)

15. Osmosis in red blood cells
Isotonic
Hypotonic
Hypertonic

17. Facilitated diffusion
Occurs when substances are not able to pass directly through the membrane. (glucose)
They enter the cell with the aid of transport proteins.
It occurs along the concentration gradient and does not require energy.
hill.com/sites/ /student _view0/chapter2/animation__how_f acilitated_diffusion_works.html

18. Facilitated diffusion

20. Transport proteins
Channel proteins are embedded in the cell membrane & have a pore for materials to cross
Carrier proteins can change shape to move material from one side of the membrane to the other

21. Active Transport Requires energy
Substances cannot pass directly through the cell membrane.
Moves against the gradient from LOW to HIGH Concentrations.
The proteins pump molecules through the cell membrane. REQUIRES ENERGY in the form of ATP.

22. Active transport
Some molecules that are pumped across the membrane include
Sodium, Potassium, and Calcium Ions

23. Active transport

24. Sodium-Potassium Pump
Most common example of active transport. Uses energy to pump sodium and potassium ions through the membrane. 3 Na in; 2 K out

25. Endocytosis/ Exocytosis
If the molecules are too large to pass through the membrane, they must use a vesicle to enter and exit. BULK TRANSPORT
Endocytosis – Big stuff entering
Exocytosis- Big stuff leaving