Ribonucleic acid (RNA) synthesis involves special modifications during and after production of the precursor RNA.
Eukaryotic mRNA is modified at its five-prime (5') end shortly after transcription commences. This involves the addition of a modified
at its 5' end which is called 5' capping.
In eukaryotes, the capping enzyme complex is attached to the RNA
Mitochondrial and chloroplast mRNA
capped by a modified nucleotide as occurs with eukaryote mRNA.