If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, the relative concentrations of solute and water are equal on both sides of the membrane. ... When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.

Hypertonic, Hypotonic, and Isotonic Solutions: An Overview

Hypertonic Solution
A hypertonic solution refers to a solution that has a higher concentration of solutes compared to another solution. In other words, it has a higher osmolarity than the solution it is being compared to. When a cell is placed in a hypertonic solution, water tends to move out of the cell to balance the concentration gradient. This can cause the cell to shrink or undergo a process called crenation.

Hypotonic Solution
On the other hand, a hypotonic solution has a lower concentration of solutes compared to another solution. It has a lower osmolarity than the solution it is being compared to. When a cell is placed in a hypotonic solution, water moves into the cell to balance the concentration gradient. This can cause the cell to swell or even burst, a process called lysis.

Isotonic Solution
An isotonic solution has the same concentration of solutes as the solution it is being compared to. It has the same osmolarity. When a cell is placed in an isotonic solution, there is no net movement of water across the cell membrane. This means that the cell maintains its shape and size without undergoing any significant changes.

Key Points:
1. Hypertonic solution: Higher solute concentration, water moves out of the cell, causes cell shrinkage (crenation).
2. Hypotonic solution: Lower solute concentration, water moves into the cell, causes cell swelling or bursting (lysis).
3. Isotonic solution: Same solute concentration, no net movement of water, cell maintains its shape and size.

Effects on Cells:
- Hypertonic solutions cause water to move out of cells, leading to cell shrinkage. This can be seen in red blood cells placed in a concentrated saline solution.
- Hypotonic solutions cause water to move into cells, leading to cell swelling or even bursting. This can be observed when plant cells are placed in distilled water.
- Isotonic solutions maintain the equilibrium of water movement, keeping the cell shape and size stable. This is the condition in which most animal cells function optimally.

Applications:
- Hypertonic solutions can be used in medical settings to draw excess water out of swollen tissues, reducing edema.
- Hypotonic solutions are commonly used in intravenous fluids to provide hydration and prevent dehydration.
- Isotonic solutions, such as normal saline, are used for various purposes, including rehydration and restoring electrolyte balance.

Understanding these concepts of hypertonic, hypotonic, and isotonic solutions is crucial in various biological and medical contexts as it helps explain the effects of different solutions on cells and their applications in practical settings.