| A | B |
|---|
| cell membrane | found in all types of cells; |
| lipid bilayer | principle component of a cell membrane; made of 2 layers of phospholipids |
| cell wall | Structure outside cell membrane in plants, fungi, and prokaryotes; function is structure, support, and shape; made of cellulose in plants. |
| 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 | the diffusion of particles across a selectively permeable membrane with the assistance of transport proteins. This process requires no energy. |
| active transport | movement of a substance from an area of low concentration to an area of high concentration; a process that requires energy. |
| hypertonic | characterizes a solution that has a higher solute concentration than does a neighboring solution. |
| hypotonic | characterizes a solution that has a lower solute concentration than a neighboring solution. |
| isotonic | solution that has the same solute concentration as surrounding solutions. |
| endocytosis | active transport that allows cell to take in materials from outside |
| exocytosis | active transport that allows cell to expell materials from the inside of the cell to the outside |
| "against" concentration gradient | from low to high concentration (active transport) |
| "with" or "down" concentration gradient | from high to low concentration (passive transport) |
