So doing work on that charged species to move it across that particular membrane. So, by the way, delta V is simply the difference in the voltage between this side of the membrane and the other side of the membrane. So this is the voltage difference, the electrical potential difference, what we call the electrical gradient. So delta G describes the amount of energy that must be transferred into the molecule or the molecule releases into the environment to basically move between the two sides of the membrane. And to demonstrate how we can use this particular equation, let's take a look at the following diagram. So, let's suppose we have a cell membrane, and in that cell membrane we have an open channel.