That free energy is captured by this importer and it is used to move these orange molecules against electrochemical gradient from a low to a high concentration, from the outside to the inside in the same direction. And so that's why we call them co transporters, simporters. In this case, they're called anti porters or exchangers, because they move in opposite directions. Now, to demonstrate a specific example, let's take a look at a very common type of Simporter. So, co transporter that we find in the membranes of E. Coli cells. And by the way, prokaryotic organisms as well as eukaryotic organisms have these secondary transporters.