So what about the function of DNA and RNA? So the entire purpose of these nucleic acids is to basically store the genetic code, the genetic information in the cell and use it to build different types of proteins. And when the time comes when we reproduce to pass that genetic information down to the offspring. So let's begin with the function of DNA. So DNA molecules are these biological molecules that store that genetic information and the genetic information is stored in the sequence of these nitrogenous bases because the backbone of the DNA molecule that consists of the sugar molecule and the phosphate essentially repeats as we go from one nucleotide to another. That does not change.