| A | B |
|---|
| diffusion | Main method that small molecules move in & out of cell. Molecules move from area of higher concentration (lots) to areas of lower concentration (little) |
| osmosis | Diffusion of water molecules through a selectively permeable membrane |
| active transport | the movement of materials through a cell membrane using energy |
| passive transport | the movement of materials through a cell membrane without using energy |
| selectively permeable | a property of cell membranes that allows some substances to pass through, while others cannot |
| transport proteins | pick up molecules outside of the cell and carry them in using energy in the process, transport proteins also carry materials out of the cell |
| cell membrane | the outside boundary of the cell; controls which substances can leave or enter the cell |
| engulfing | a method of active transport, the cell membrane surrouds, or engulfs the particle; once the particle is engulfed the cell pinches off a piece and forms a vacuole within the cell, energy is used in this process |
