| A | B |
|---|
| cell membrane | part of the cell's outer boundary; contains a lipid bilayer. |
| phospholipid bilayer | principle component of a cell membrane |
| passive transport | Movement of substances across the cell membrane from regions of high concentration to regions of low concentration; occurs without the cell expending energy.. |
| diffusion | process by which substances spread through a liquid or gas from regions of high concentrations to regions of low concentration. |
| osmosis | diffusion of water through a selectively permeable membrane. |
| facilitated diffusion | type to passive transport; movement of materials from high to low concentration using proteins |
| active transport | a process that requires energy to move materials--either large molecules or from low to high concentration |
| hypertonic | a solution that has a higher solute concentration, causing water to move out of a cell |
| hypotonic | a solution that has a lower solute concentration, causing water to move into a cell |
| isotonic | solution that has the same solute concentration as surrounding solutions. |
| protein pumps | moves ion through proteins from low to high concentration |
| endocytosis | moving large materials into cells using energy |
| exocytosis | movement of large materials out of cells using energy |
| concentration gradient | difference in concentration of particles in a solution |
| semipermeable | lets some materials through, but not others |
| plasma membrane | regulates what goes in and out of a cell; made of a phosoholipid bilayer |
| homeostasis | maintain a stable internal environment |
