1. “Salad” Notes Movement of molecules in and out of the cell
10/2014

2. Natural Movement of Molecules
Concentration: the strength of a solution.
Concentration Gradient:
Describes a situation of solutions with different concentrations in a space.
Molecules move from High concentration to Low concentration

3. Passive Transport
The movement of substances across the cell membrane without the use of energy
Flows from high concentration to low concentration
Includes diffusion, osmosis, & facilitated diffusion

4. Diffusion
Movement from high to low concentration until an equal distribution of those molecules is reached in all areas
Movement of ANY small uncharged molecules

6. Osmosis
Diffusion of water from high to low concentration

7. Tonicity Osmotic pressure AKA turgor when we talked about plants!
Hypertonic – higher concentration than internal contents
Water leaves cell trying to dilute external concentration
Isotonic – same concentration
Even water movement
Hypotonic – lower concentration than internal contents
Water moves into cell to dilute internal concentration

9. Tonicity

11. Facilitated Diffusion
A carrier protein moves the molecules across the cell membrane down the concentration gradient.

12. Active Transport
Movement from low to high concentration
Requires ENERGY & a transport protein