So let's pretend that this is the five end of our premna that is synthesized directly following the process of transcription. So basically what we do is we add this guanacine nucleotide via the following triphosphate bond. The reason it's called a triphosphate bond or a triphosphate linkage is because we have one, two, three phosphorus atoms. And the reason it's called a five to five triphosphate linkage is because that linkage is between the fifth carbon on this sugar and the fifth carbon on this ribosugar. So this is the five guanosine triphosphate cap. Now, the question is why exactly should we add this cap to our pre mRNA molecule?