| A | B |
|---|
| cell membrane | regulates what enters & leaves the cell |
| three other names for the cell membrane | lipid bilayer, plasma membrane, fluid mosaic model |
| phospholipid | molecule found in the cell membrane with two non-polar tails made of fatty acids (lipids), joined to a polar head that contains phosphorus |
| lipid bilayer | double layer of phospholipids that makes up the cell membrane |
| polar molecule | molecule in which positive & negative charges are unevenly distributed |
| channel proteins | proteins in the cell membrane that act like passageways through which only certain molecules pass |
| receptor proteins | proteins in the cell membrane that transmit information into the cell by changing shape in reaction to other molecules |
| marker proteins | proteins in the cell membrane that identify the cell |
| passive transport | movement of molecules in and out of the cell involving no energy from the cell |
| diffusion | process in which substances move from an area of higher concentration to an area of lower concentration |
| osmosis | diffusion of water through a cell membrane |
| solute | a substance that can be dissolved in H2O |
| solvent | a liquid substance in which a solute is dissolved |
| isotonic solution | solution surrounding a cell in which the concentration of solutes outside the cell is the same as inside the cell, with no major movement of water across the cell membrane |
| hypertonic solution | solution surrounding a cell in which the concentration of solutes outside the cell is greater than inside the cell; water will move out of the cell |
| hypotonic solution | solution surrounding a cell in which the concentration of solutes outside the cell is lower than inside the cell; water will move into the cell |
| equilibrium | the state in which the concentration of water molecules is equal on each side of a cell membrane, inside & outside of cell |
| plasmolysis | loss of water by a cell |
| turgor | pressure inside a cell caused by the presence of water |
| active transport | one-way movement of substances across a membrane that requires energy |
