1. How do materials get in and out of a cell ??
AIM:
How do materials get in and out of a cell ??

2. **THROUGH THE CELL MEMBRANE!!!

3. What is the function of the cell membrane?
it is SELECTIVELY PERMEABLE.
What does PERMEABLE mean?
-the ability to let things pass through.
**The cell membrane only allows certain substances to enter and leave the cell.
this helps maintain HOMEOSTASIS.
HOW???
It’s in all in the structure!

4. What is the structure of the cell membrane?
cell membrane structure:

7. - the membrane is made of a double layer of LIPIDS with PROTEINS in it.
some of the proteins form a passageway or pore from the outside of the cell to the inside of the cell.
- Small molecules like H2O, O2, CO2 & glucose are able to DIFFUSE through the cell membrane b/w the lipid molecules.

8. What is DIFFUSION????
process in which materials move from an area where they are more concentrated to an area where they are less concentrated.
(move from high conc. to low conc.)
WHY???
DRAW IT !
It’s like going downhill, so…
**DOES NOT REQUIRE ENERGY USE !
**ALSO CALLED PASSIVE TRANSPORT! (WHY?)

9. What is OSMOSIS?? the diffusion of WATER!!! What is ACTIVE TRANSPORT?
movement of particles across a cell membrane from an area of LOW conc. To an area of HIGH conc.
requires the use of energy (ATP).
Like going uphill (opposite of diffusion).

10. HOW?
carrier proteins in membrane form tubes that transport particles in or out.
Draw it!
How does it help a cell??
1- to keep wastes out of the cell or to store large amounts of needed materials.
2- to get large particles in/out of the cell.

11. The cell membrane is said to be SELECTIVELY PERMEABLE
The cell membrane is said to be SELECTIVELY PERMEABLE. What does this mean??
it means that the cell membrane only allows certain substances to pass in or out of the cell.
It “selects” what can enter and leave the cell.