Essay by sam90High School, 10th gradeA, February 2006

download word file, 8 pages 0.0

How does different concentration of sucrose solution affect the movement of a solution through osmosis?

Background Information

Osmosis is the movement of water molecules from an area of high concentration to an area of low concentration; diffusion of water across a cell membrane is osmosis. Osmosis is used by selectively permeable membrane that will let water cross freely, except big molecules and ions. The cell membrane will also absorb Co2, O2, H2O, Nh2 (amino acids), C6H12O6 (glucose). But will not let larger molecules in like C12H22O11 (sucrose), Ch2O (starch) and protein. If the solution contains a higher concentration than the cell, then cell will lose water by osmosis and may shrivel (plasmoylsed). If the solution has the same volume as the cell then there will be no change in the cell and it will stay the same. If the concentration is lower than the cell, the cell will gain water so therefore swell and may burst so the cell becomes turgid; this is due to osmotic pressure.

(These net movements are called HYPERTONIC, ISOTONIC, and HYPOTONIC.)


I think there will be a hypertonic net movement. The reason for my prediction is, because the concentration will be higher than the water in potato and it is going to be a sucrose solution. I know that sucrose can't be absorbed by osmosis, because it's too bigger molecule. So the potato will lose water so the net movement will be hypertonic. Therefore I predict that the mass of the potato will decrease and cells become plasmoylsed.

Key Factors

Things I could change are the concentration of sucrose (Ch2O), which will affect volume of water the potato will lose and how fast it will lose or gain. I'll be using five boiling tubes with a piece of potato each and filled with...