|MadSci Network: Cell Biology|
Your question is one I usually use as a bonus question for my Introductory Biology class. When it comes to cells bursting, plant cells respond differently than animal cells. When an animal cell is put into distilled water it will swell up and burst. This is due to the fact that an animal cell is hypertonic to the pure water surrounding it so, water enters the cell until the cell bursts. This is similar to putting too much air into a balloon. It pops. When a plant cell is put into distilled water, water will move in for the same reasons water enters an animal cell. The solution inside the cell is hypertonic to the solution (in this case, distilled water) surrounding the cell. The thing that keeps the plant cell from bursting is the cell wall that surrounds the plasma membrane. As water enters the cell the cell membrane presses against the cell wall creating a turgor pressure, keeping the plant upright. The plant cell wall will limit how much water can enter the cell. This keeps the cell from bursting. If the plant cell wall was not there, the plant cell would behave just like the animal cell. It is possible to treat plant cells with the enzymes, pectinase and cellulase, to degrade the cell wall making a plant cell protoplast. If this cell is placed in distilled water it would swell up and burst. There are many sites on the Internet that discuss a cells responses to a hypotonic, hypertonic or isotonic environment. One such site is http://www.biologie.uni-hamburg.de/b- online/e22/22c.htm. There is also another post at http://www.madsci.org/posts/archives/2004- 02/1076447262.Bt.r.html that deals with these same topics that might be of interest to you. To answer the last part of your question, the only thing I can think of that would make a plant cell burst is that if a plant cell freezes the ice crystals formed inside the cell could puncture the membrane causing it to leak when the plant thawed.
Try the links in the MadSci Library for more information on Cell Biology.