| A | B |
|---|
| cell | a membrane-covered structure that contains all of the materials necessary for life |
| diffusion | the movement of particles from an area where their concentration is high to an area where their concentration is low |
| osmosis | the diffusion of water across a cell membrane |
| passive transport | the diffusion of particles through proteins in the cell membrane from areas where the concentration of particles is high to areas where the concentration of particles is low |
| active transport | the movement of particles through proteins in the cell membrane against the direction of diffusion; requires cells to use energy (in the form of ATP) |
| cell membrane | a phospholipid layer that covers a cell's surface and acts as a barrier between the inside of a cell and the cell's environment |
| endocytosis | the process in which a cell membrane surrounds a particle and encloses it in a vesicle to bring it into the cell |
| exocytosis | the process used to remove large particles from a cell; during this process, a vesicle containing the particles fuses with the cell membrane |
