click below
click below
Normal Size Small Size show me how
Chapter 4
Cells and Their Environment
| Term | Definition |
|---|---|
| passive transport | movement across the membrane that requires NO energy |
| concentration gradient | a difference in the concentration of a substance |
| equilibrium | concentration is equal throughout a space |
| diffusion | the movement of a substance from an area of high concentration to an area of low concentration |
| osmosis | the movement of water |
| hypertonic solution | water moves out, cells shrink |
| hypotonic solution | water moves in, cells swell |
| isotonic solution | no water movement because it is equal |
| facilitated diffusion | passive transport with help from carrier proteins |
| carrier protein | helps with facilitated diffusion |
| active transport | movement across the membrane the requires energy, low concentration to high concentration |
| endocytosis | movement of a substance into a cell |
| exocytosis | movement of a substance out of a cell |