And the amount of energy that is released in this process is greater than the amount of energy that is used to actually break these bonds. And so the sum of those two values will give us a negative free energy. And what that means is this process of the movement of these potassium ions across is an overall spontaneous process. It will take place spontaneously because free energy is released into the environment. Now, the second function of the selectivity filter, this sequence of five amino acids within this restricted area is to basically give that specific channel its ion specificity. So we see that the selectivity filter also determines the specific nature of that ion channel, its ability to actually move these potassium ions across that membrane.