Question

What is mediated permeability? discuss the types of medicated permeability.

Answer 1

Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.

Answer 2

The permeability of a membrane for the molecules totally depends on the transport proteins fixed in the membrane. This phenomenon is called mediated permeability.

Two molecules of same size, shape, structure and lipid solubility can show different permeability through a common membrane. Some moves faster and some slower depending upon the transporting molecule inside the membrane that allows the passing of molecules. This is called mediated permeability.