1. Cell Transport
7-3
Pgs

2. Cell Membrane Cell membrane regulates what leaves and enters the cell.
It is a lipid bilayer with proteins embedded in the layer.

3. Phospholipids Phosphate head- polar “likes” water
Lipid tail- 2 fatty acids- non-polar- does not “like” water

4. Phospolipid Bilayer There are 2 types of proteins in the lipid bilayer
Integral Proteins- transport substances across membrane
Peripheral Proteins- bind to the bilayer temporarily, perform various cellular processes.

5. Phospholipid Bilayer
Cholesterol plays an important role in maintaining the integrity of the membrane.
Keeps it firm and from becoming too permeable.
Carbohydrates- Act as cell markers, allow cells to identify each other.

6. Cell Membrane Video

7. Diffusion
All cells must exist in a liquid environment in order to survive.
A solution is a mixture of two or more substances.
Solute- substance dissolved into the solvent
Solvent- substance solute dissolves into.
Ex- iced tea mix is the solute, water is the solvent

8. Diffusion Particles are constantly moving in a solution.
Particles tend to move from an area of high concentration to an area of low concentration, this is called diffusion.
Movement from high to low concentration is called the concentration gradient

9. Diffusion

10. Equilibrium
Particles move from high to low conc. until they are the same throughout the system, this is called equilibrium

11. Diffusion
Since particle movement is random, diffusion occurs across the membrane without the use of energy.
Called Passive Diffusion

12. Osmosis
Osmosis is the diffusion of water across a selectively permeable membrane.

13. Osmosis
Water will move across a membrane until the concentrations of water and the solute are equal, this is an isotonic solution.
Hypertonic solution- when there is more solute then water. concentrated
Hypotonic solution- when there is more water then solute. dilute

15. Facilitated Diffusion
Proteins in the cell membrane allow some substances pass through easier then others.
Still follows concentration gradient
Ex- doorman at a club, lets some people in easier then others

16. Active Transport
Sometimes particles have to move from low to high concentration, against the concentration gradient.
This requires energy and is called active transport.
Ex- swimming against the current of a river.
Use proteins to carry particles across

18. Endocytosis and Exocytosis
Particles that are too large to pass through the membrane other ways
Endocytosis- the cell membrane folds around an object and envelops it.

19. Endocytosis and exocytosis
2 types of endocytosis
Phagocytosis- used for taking in food particles
Pinocytosis- used for taking in liquids

20. Exocytosis
Exocytosis is a process used to release substances from the cell.
Vacuole fuses with the cell membrane and forces contents out of cell