BIOL 3200 Midterm: Transport
Document Summary
Along the concentration gradient (higher concen- tration to lower concentration) Continue until equilibrium reached or something happens to cell. May not require semipermeable membrane (semipermeable = selectively permeable) Energy required can be atp or proton motive force. Against concentration gradient (lower concentra- tion to high concentration) Will not reach equilibrium but something can still happen to cell. Requires semipermeable membrane (semiper- meable = selectively permeable) Examples= na/k pump, pinocytosis, phagocyto- sis, group translocation. For passive transport to occur, you don"t need a membrane. But if a membrane is there then it is semi-permeable membrane: active doesn"t happen unless there is a semi-permeable membrane. Osmosis: passive transport, diffusion, movement of water, hypertonic vs hypotonic solutions . If you sprain your ankle, soak it in salt water: swelling goes down, fluid in foot will be drawn out by the hypertonic solution in your foot.
