Expert: Walter Hintz - 11/11/2007

Question
Could you please explain to me the process of Osmosis, i was ill when they explained it in class. So i need to know what Osmosis is and the process, i was hoping you could help me out. Could you please explain it simply though.

Answer
Hi lauren
 By definition Osmosis is movement of water from an area of high concentration to an area of low concentration across a semipermeable membrane.
 Picture a living cell with a concentration of salt at 9%.  Now we place the cell into water with a salt concentration of 5%. Where is there more water?  Inside the cell there is 91% water and outside there is 95% water so water enters the cell by osmosis.
 Did you ever sprinkle salt on an earthworm.  It wiggles! Why? Because the worms body fluid is about 1 % salt (99% water) and on the outside there is a lot of salt and less water.  Therfore water leaves the worm by osmosis causing it to dehydrate.