Diffusion, Osmosis and Tonicity

The cell's transmission system keeps it stable and thriving throughout its existence. A cell contains a semi-permeable membrane that prohibits harmful substances from entering the cell. According to these results, the cell is initially in equilibrium with the extracellular solution (isotonic).

When immersed in a hypertonic solution that is more concentrated than intracellular fluids, the cell loses water into the solution down the concentration gradient through the semipermeable membrane, causing the cell to become flaccid. Time is required to allow water to pass from the intracellular to the extracellular space. On the other hand, when a cell is placed in hypotonic solution (the intracellular fluid is highly concentrated about the extracellular fluid) water molecules move through the semipermeable membrane into the cell down the down the concentration gradient. Due to the continued intake of water into the cell and the delicate nature of the cell membranes, the cells usually burst upon reaching the maximum size.

Unlike in diffusion where the solute moves, in osmosis the solvent move from a region of its high concentration to an area of low concentration. Concisely, a semi-permeable cell membrane is vital for the cell to survive. There must be a controlled amount of water molecules inside and outside the cell to maintain an equilibrium and homeostasis.