What is the difference between diffusion and concentration gradient? How are each important to the process of cellular communication?

Question

What will be an ideal response?

Answer 1

Diffusion (the force that moves molecules from areas of high concentration to areas of low concentration) is a tendency for molecules to distribute themselves equally within a medium such as air or water. In more formal terms, diffusion pressure moves molecules along a concentration gradient from areas of high concentration to areas of low concentration. During the action potential, these two forces are exceedingly important. For instance, once the sodium channels open, sodium rushes into the neuron, in part, because it moves along the concentration gradient. Once inside, the sodium will also diffuse down the length of the axon, thereby re-initiating the action potential at the next node of Ranvier.