Cells react differently in hypotonic, isotonic, and hypertonic solutions. In a hypotonic solution, water rushes into the cell causing it to expand or even burst. In an isotonic solution, there is no net flow of water, keeping the cell stable. In a hypertonic solution, water leaves the cell, causing it to shrivel. These reactions are due to the semipermeable nature of cell membranes and the concentration of solutes.
Hypertonic: A hypertonic solution is any external solution that has a high solute concentration and low water concentration compared to body fluids. In a hypertonic solution, the net movement of water will be out of the body and into the solution.
What happens in a hypertonic solution is osmosis. Water moves from where there is a lower concentration of solute to where there is a higher concentration of solute. Thus, in a hypertonic solution, water leaves the cell and moves to the environment. This causes the cell to shrivel. For example, when we are severely dehydrated our red blood cells can be in a hypertonic environment. This causes the cells to shrivel and can even lead to cell death.
Hypotonic: A hypotonic solution is a solution that has a lower concentration of solute compared to the cell. Solutions are mixtures composed of a solute and a solvent. The solute is the substance present in a lower amount, and the solvent is the substance present in greater amount. A hypotonic solution example is salt water. The salt is the solute, and the water is the solvent.
Isotonic: An isotonic solution is defined as two solutions of equal concentrations of solutes and water separated by a semipermeable membrane to allow water to move freely in and out of a cell.
A review of hypotonic, hypertonic and isotonic solutions, how they lead to plasmolysis, cytolysis and dynamic equilibrium. Remember that "hypertonic", "hypotonic" and "isotonic" are all relative terms (like "bigger" or "shorter"). A hypertonic solution is saltier then something else (in this case, the cell that's placed in it). It might not be very salty at all, it just has to be MORE salty relative to another solution or object.
Time-stamped Table of Contents: 0:00-0:15 Should You Drink Sea Water? 0:21- 0:33 Picky Cells 0:33-0:46 Types of Solutions 0:46-1:10 The Cell Membrane 1:10-1:44 Concentration, Diffusion and Dynamic Equilibrium 1:44- 2:11 Ion Dipole Interactions 2:11- 3:10 Hypertonic Liquid & Plasmolysis 3:10- 3:30 Hypotonic Liquid & Cytolysis 3:30-3:51 Isotonic Liquid 3:52-4:46 Should You Drink Sea Water?