Red blood cells, in solutions

The membranes of living cells act as semipermeable membranes. Consequently, if you put a living cell into seawater, it loses water through osmosis and becomes dehydrated. Figure 13.11 shows red blood cells in solutions of various... 

FIGURE 13.11 Red blood cells in solutions of different concentration (a) When the solute concentration of the surrounding fluid is equal to that within the cell, there is no net osmotic flow, and the red blood cell exhibits its typical shape, (b) When a cell is placed in pure water, osmotic flow of water into the cell causes it to swell up. Eventually it may burst. 

Shown here are color-enhanced electron micrographs of red blood cells in solutions of various osmotic pressures. W The osmotic pressure of the solution is greater than that of the cell the cell has collapsed. The osmotic pressure of the solution is equal to that of the cell the cell has its normal round shape with depressed center. The osmotic pressure of the solution is less than that of the cell the cell has a bloated shape. 

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