And we also have trace amounts of other types of RNA molecules as we'll see in just a moment. So let's begin by focusing on these three RNA molecules and let's begin with messenger RNA. Now the messenger RNA molecule is basically the molecule that is eventually used by the ribosomes of our cells to synthesize the proteins in a process known as translation. So in prokaryotic cells what happens is we take the DNA of that prokaryotic cell and then we transcribe the mRNA molecule and then that mRNA molecule can be used directly to synthesize the protein or proteins. So the mRNA molecule in prokaryotic cells can sometimes code for more than one protein but in eukaryotic cells it's slightly different. In eukaryotic cells we take the DNA and then we produce a precursor mRNA a pre mRNA molecule.