Question

Define the following: Tonicity

Answer 1

Permeability

1. Permeability is the state, situation, or attribute of a substance (such as a biological membrane) that allows molecules to pass through it.
2. It's the rate at which passive diffusion takes place across the membrane.

Tonicity

1. The ability of an extracellular solution to enable water to migrate into or out of a cell via osmosis is referred to as tonicity.
2. Isotonic, hypertonic, and hypotonic are used to describe whether a solution will enable water to flow in and out of a cell.
3. Solutions are considered to be isotonic if the concentration of water molecules and the solute on either side of the cell membrane are the same causing no net water flow in the isotonic solution.
4. In hypotonic conditions, the solute content of the solution outside the cell is lower than the solute concentration of the fluids inside the cell causing water molecules from the outside to move inside.
5. The solution outside the cell is more concentrated than the solution inside the cell under a hypertonic situation causing water molecules from the cell's interior will move to the cell's exterior.