| A | B |
|---|
| diffusion | movement of molecues from area higher concentration to area lower conc |
| active transport | movement of materials from an area of lower concentration to area higher conc. requiring cell to expend energy |
| energy | active transport requires a cell to expend |
| concentration gradient | difference in concentration of molecules across a distance |
| equilibrium | concentration of molecules will be the same throughout the space the molecules occupy |
| carrier proteins | these are in the membrane & move molecules that are too large or not soluble in lipids across the membrane |
| too large or not lipid soluble | molecules like this can't get across membranes without carrier proteins |
| facilitated diffusion | process used for molecules that can't readily diffuse through cell membranes, even when there is a concentration gradient across the membrane |
| contractile vacuole | organelles that remove water from a cell or unicellular organism |
| ion channels | membrane proteins that transport ions from higher to lower conctration |
| phagocyte | cells in animals used to ingest bacteria and viruses that invade the body |
| vesicle | pouch that pinches off from the cell membrane and becomes a membrane-bound organelle during endocytosis |
| sodium potassium pump | a carrier protein that transports sodium and potassium ions up their concentration gradients |
