1. Cell Membrane - allows materials in or out of the cell Consists of:
1) Lipid Bilayer- 2 layers of fat tissue
2) Proteins- embedded into membrane
- help move materials across
Cell Membranes are:
Selectively Permeable- controls what materials are
allowed to cross.

2. CELL MEMBRANE

3. Cell Membrane Processes
Diffusion
- movement of materials from high to low
concentration
- diffusion requires no energy
- continues until equilibrium is reached

4. Osmosis
- the diffusion of water
* Water moves across when materials can’t

5. Osmosis Continued:
- cells may shrink or burst due to osmosis

6. * Does not require energy!*
Facilitated Diffusion
- use of proteins in the membrane that aid
diffusion
* Does not require energy!*

7. Active Transport
- using energy to move materials across the
cell membrane.
- used to fight natural diffusion

8. Cell Transport Vocabulary Review
A. Movement of water from high to low concentration
B. The use of energy to move particles in/out of a cell
C. Organelle that moves materials in/out of a cell
D. Process of moving materials from high to low concentration
E. Moving particles across a membrane without needing energy
F. The use of proteins to move large particles in/out of a cell