What they also do is they actually increase the resistance of the DNA molecules to hydrolysis. So remember, anytime we have an Esther Bond, that Esther bond can undergo the process of hydrolysis in which a nuclearphile essentially attacks that bond and breaks that bond. But in this particular case, because we have negative charges on these phosphate groups, these negative charges will repel the negative charge found on the nucleophile. And because of this electrostatic repulsion, that will stabilize the structure of the DNA molecule and increase its resistance to hydrolysis in the same exact way as this, the absence of this oh, on the deoxyribo sugar also increase the resistance of the DNA to hydrolysis. So these two effects increase and stabilize the structure of DNA. And so that's exactly why DNA molecules are generally much more stable than RNA molecules and are able to resist hydrolysis with a much higher potential.