The solute potential (also called the osmotic potential) of a solution is a measure of the effect of dissolved solutes on the osmotic behavior of the solution. The following statement presents an opportunity for confusion, so study it carefully: * the greater the solute concentration of a solution, the more negative its solute potential, and the greater the tendency of water to move into it from another solution of lower solute concentration (and less negative solute potential). Owing to the rigidity of the cell wall, plant cells do not burst the way animals cells do when placed in pure water; instead, water enters plant cells by osmosis until the pressure potential exactly balances the solute potential. At this point, the cell is turgid; that is, it has a significant positive pressure potential. The overall tendency of a solution to take up water from pure water, across a membrane, is called its water potential and is represented as (figure 35. 2).