click below
click below
Normal Size Small Size show me how
3.3,3.4,3.5
| Term | Definition |
|---|---|
| cell membrane | the plasma membrane that forms a boundary between a cell and the outside |
| phospholipid | a molecule composed of a charged phosphate group, glycerol, and two fatty acid chains |
| fluid mosaic model | describes the arrangement of the molecules that make up a cell membrane |
| selective permeability | means the cell membrane allows some, but not all materials to cross |
| Receptor | a protein that detects a signal molecule and performs an action is response |
| Passive transport | the movement of molecules across a cell membrane without energy input from the cell |
| diffusion | the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration |
| concentration gradient | the different in the concentration of a substance from one location to another |
| Osmosis | water molecules move across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration |
| isotonic | what a solution is to a cell if it has the same concentration of dissolved particles as the cell |
| hypertonic | has a higher concentration of dissolved particles than a cell |
| hypotonic | has a lower concentration of dissolved particles than a cell |
| facilitated diffusion | the diffusion of molecules across a membrane through transport proteins |
| active transport | drives molecules across a membrane from a region of lower concentration to a region of higher concentration |
| endocytosis | the process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane |
| exocytosis | the opposite of endocytosis, is the release of substances out of a cell by the fusion of a vesicle with the membrane |
| phagocytosis | a type of endocytosis in which the cell membrane engulfs large particles |