| A | B |
|---|
| Passive transport | movement of substances into and out of a cell without the use of energy. |
| Active transport | movement okf substances through an membrane with the use of energy. |
| ATP | Adenosine triphosphate, a coenzyme composed of a base, a sugar, and three phosphate groups that store and control the release of energy within a cell. |
| Plasma membrane | a selective permeable, molecular boundary that separates the cytoplasm of a cell from the external environment. |
| Diffusion | passive transport by which substances move from a region of higher concentration to a region of lower concentration. |
| Osmosis | diffusion of water through a selective permeable membrane. |
| Facilitated diffusion | transport of molecules into cells with the aid of "carrier" proteins embedded in the plasma membrane. |
| Exocytosis | a form of active transport by which cells move molecules, particles, or other cells contained in vesicles across the plasma membrane to the cell's environment. |
| Endocytosis | a type of active transport that imports particles or small cells into a cell. |
| Plasmolysis | the shrinking of a plant cell away from its cell wall when placed ina lower solute concentration than found inside the cell. |
| Homeostasis | the maintenance of fairly constant internal conditions. |
| Hypertonic solution | a solution containing a higher solute concentration than a cell. |
| Hypotonic solution | a solution having a lower solute concentration than a cell. |
| Isotonic solution | a solution having a concentration equal to that of a cell. |
