Post-transcriptional Modification of mRNA:
This animation shows the modification of mRNA after Transcription from a primary transcript to a mature transcript. A methylated guanine cap is added to the 5' end of mRNA and a poly-A tail is added to the other end. The cap and tail protect the mRNA from enzyme degradation and aid its attachment to the ribosome. Introns (non-coding) sequences are spliced out of the mRNA and exons (coding) sequences are spliced together. The mature mRNA transcript will then undergo Translation.

High school biology website with flash animations. Requires current Flash player.