And what that means is they don't have a beginning, they don't have an end, they are continuous, as we see in the following circle. Now, linear DNA molecules and circular DNA molecules are actually relatively large and relatively long. And if we zoom in into the cell of either bacterial cells or our own human cells, we're not going to see these DNA molecules existing in the following form. Instead, the linear DNA molecules found in our own cells and the circular DNA molecules found in bacterial cells are going to condense via this process of super coiling. Now, super coiling basically serves two important biological purposes. Number one, we actually want to be able to fit that long DNA molecule into the nucleus of our own cells and into the cell structure of that biological cell.