A red blood cell placed in pure water would _____.

A red blood cell placed in pure water would _____.

A) swell initially, then shrink as equilibrium is reached.

B) swell and burst

C) neither shrink nor swell

D) shrink

Answer: B) swell and burst

If you ever live-wired a red blood cell and dropped it into pure water, it would swell and pop immediately. This happens through osmosis which is the process of movement of the solvent or the water from the side of the lower solute concentration to the side of the higher solute concentration. The interior of the cell is denser which results in having a higher concentration of solutes than the water outside of the cell. Therefore, water molecules move from an area of low concentration into the cell so that an equilibrium is achieved. As a result of entering of the water into the cell, the cell becomes swollen. Contrary to the other plant cells which contain the hard cell walls, the red blood cells do not possess such a component. As a result, and under the pressure of progressively increasing concentration of the solute in the solution on the one hand and the perpetuation of the process of osmosis on the other hand, the flexible cell membrane pops and bursts at one point or another. This process is known as haemolysis and results in the destruction of the red blood cell.