ok so i have 3 beakers of water one filled with sea water, one with distilled water and one filled with salt water.i put a piece of potatoe in each one (all same size) and left them in there for three days. what i need to know is if the potatoe cells will get bigger, smaller or stay the same. can somone pleeease help me!
2006-09-07 12:16:30 · 1 answers · asked by Anonymous in Science & Mathematics ➔ Biology
This is a question about osmosis.
Osmosis is the natural tendancy for water to flow across a membrane into areas with lots of stuff to dissolve. Think of it this way - water molecules are polar, like little magnets, and they LIKE to be stuck to stuff that's dissolved in them. If they can go from a place with few dissolved things to lots of dissolved things, they will!
In your example, the distilled water is the easy one - it's got absolutely nothing in it, so it's going to go anywhere it can. ESPECIALLY inside cells that are in contact with it. That piece of potato will swell right up as the water comes in. Poor potato.
On the other hand, both the salt water and the ocean water have lots of things dissolved in them. While SOME plants have adapted to this kind of environment, we both know that salt water will kill most of them, and this is why! Instead of adding water to the plant, the dissolved salt will suck it right out of them, shrivelling them up, including your potato slice. Poor potato.
The only exception would be if you happen to have a salt solution that is not entirely saturated. If you added just the right amount of salt to the water so that the osmotic pressure was the same outside as it was inside of the potato cells, then the water won't go anywhere overall. Good luck getting that balance right without a fair amount of experimentation, though.
All in all, I'd rather be the experimentor than the potato in this question. Hope that helps!
2006-09-07 12:30:43 · answer #1 · answered by Doctor Why 7 · 0⤊ 0⤋