So notice that the phosphate group contains a negative charge. And this means two important things. Number one, when we place our DNA or RNA molecule into an aqueous solution, which is a solution found in our cells and inside the nuclei of our cells, the structure of that DNA molecule and RNA molecule will basically exist in such a way as so as to make sure that these phosphate groups actually interact with the polar water molecules. And as we'll see in our discussion on the double stranded helix structure of DNA molecules, these phosphate groups actually are found on the surface of that double helix because they are able to interact with the hydrophilic water molecules. So once again, this means that in an aqueous environment, these hydrophilic regions, these hydrophilic phosphate groups will interact with the polar water molecules to stabilize the structure of DNA. Now, that's not the only thing that these phosphate groups actually do.