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Cell Membranes
cell membranes and crossing the membrane
Term | Definition |
---|---|
phospholipid | forms bilayer of cell membrane with nonpolar tails sandwiched in the middle |
transport protein | membrane protein that lets polar, charged or large materials in or out of the cell |
receptor protein | membrane protein that binds to a signal molecule |
diffusion | movement from areas of higher to areas of lower until equilibrium |
equilibrium | even distribution or balance so no net change occurs |
solute | material dissolved in a solvent |
solvent | liquid that dissolves solutes |
facilitated diffusion | movement across a cell membrane down the gradient through a transport protein |
passive transport | any movement across a cell membrane down the gradient without additional energy |
active transport | movement against the gradient from lower areas to higher areas using energy |
protein pump | transport protein that forces materials across the membrane against their gradient |
exocytosis | when vesicle fuses with cell membrane to transport larger stuff OUT |
endocytosis | when vesicle forms from cell membrane to transport larger stuff IN |
permeable | allowed to pass across a membrane |
selectively permeable | lets some stuff across a membrane but blocks other stuff |
osmosis | facilitated diffusion of water down its gradient across a membrane |