Explain the terms isotonic solution, crenation, and hemolysis.

Osmosis is the movement of water molecules across a selectively permeable membrane from a region of low solute concentration (high water concentration) to a region of high solute concentration (low water concentration). The purpose of osmosis is to achieve an equilibrium where the concentrations of solutes are equal on both sides of the membrane.

Tonicity is the relative concentration of solutes in a solution outside a cell compared to the concentration of solutes inside the cell. It determines the direction of water movement across the cell membrane through osmosis. There are three types of tonicity: isotonic, hypertonic, and hypotonic.

An isotonic solution is a solution with the same solute concentration as the solute concentration inside the cell. In this condition, the water movement across the cell membrane is balanced, meaning that the cell neither gains nor loses water. Consequently, cells maintain their normal shape and function.

Crenation is the process where a cell shrinks due to water loss, resulting from osmosis when the cell is placed in a hypertonic solution. A hypertonic solution is a solution with a higher solute concentration than the solute concentration inside the cell. In this environment, water moves out of the cell, causing crenation. The cell loses its typical round shape, and its function may be impaired due to the decreased water content.

Hemolysis is the process where a cell swells and eventually bursts due to the intake of water when placed in a hypotonic solution. A hypotonic solution is a solution with a lower solute concentration than the solute concentration inside the cell. In this case, water moves into the cell, causing it to swell up. If the swelling is too severe, the cell membrane will rupture and release its contents, leading to cell death. This phenomenon is called hemolysis. To sum up, an isotonic solution maintains cell shape and function due to balanced water movement, while crenation and hemolysis occur when cells are placed in hypertonic or hypotonic solutions, respectively, causing a disturbance in the water movement across the cell membrane.