Question

How do hypertonic solutions affect plant cells?

Answer 1

The solutions which have a higher concentration of solutes outside the cell as compared to the inside of the cell are called a hypertonic solution.

Complete answer:
A homogenous mixture of two or more substances is called a solution. They can exist in any phase. The substances that get dissolved in other substances are called solutes, and the other substance here is called the solvent. Solvents provide a medium for the dissolution of solutes. Based on the concentration of the solutes concerning a cell, they can be differentiated into three categories-

1.Hypertonic solution- The concentration of solutes is higher outside the cell.
2.Hypotonic solution- The concentration of solutes is higher inside the cell.
3.Isotonic solution- The concentration of solutes is equal outside and inside the cell.

When the cells are kept in a hypertonic or hypotonic solution, the movement occurs due to the presence of a- concentration gradient between them. In an isotonic solution, no movement occurs, and the cell is in a state of equilibrium.
When a plant cell is placed in a hypertonic solution, the outside of the cell has more solutes and less water or solvent as compared to the inside of the cell. The plant cells will lose water through the process of osmosis. Osmosis is the process through which solvent molecules pass through a semipermeable membrane. The movement occurs from the region of lower solute concentration to the region of higher solute concentration. Water will diffuse out from the cells of the plant through their cell membrane to the hypertonic solution. The movement of water outside will result in the shrinking or plasmolyzing of the cell. Hence, the size of the cell will decrease. The movement of solvent will occur till the equilibrium is reached, and the concentration gradient is nullified.

Note: When the plant cells are placed in a hypotonic solution, the movement of solvent occurs from the outside to the inside of the cell. The solute concentration is higher inside the cell. This results in the swelling of the cell, and its size increases. The cell becomes turgid.