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Transport
| Term | Definition |
|---|---|
| semi-permeable | membranes that allow some substances through but not others |
| cell membrane (aka plasma membrane) | A cell structure that controls which substances can enter or leave the cell. |
| cytoskeleton | A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement |
| active transport | The movement of materials through a cell membrane using energy. |
| carrier protein | a protein that transports substances across a cell membrane |
| concentration gradient | A difference in the concentration of a substance across a distance. |
| diffusion | Movement of molecules from an area of higher concentration to an area of lower concentration. |
| endocytosis | A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane. |
| exocytosis | a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane. |
| osmosis | Diffusion of water through a selectively permeable membrane |
| passive transport | The transportation of materials across a plasma membrane without using energy. |
| facilitated diffusion | A process in which substances are transported across a plasma membrane with the concentration gradient with the aid of carrier (transport) proteins; does not require the use of energy. |
| homeostasis | A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level |
| isotonic | Having the same solute concentration as another solution. |
| hypertonic | Having a higher concentration of solute than another solution. |
| hypotonic | Having a lower concentration of solute than another solution |