How do eukaryotic cells process mRNA before translation?

Eukaryotic cells undergo several crucial steps to process mRNA before it is translated into proteins. One of the most significant steps is splicing. During transcription, the initial RNA molecule, known as pre-mRNA, contains both exons (coding regions) and introns (non-coding regions). Introns are non-coding sequences that need to be removed to produce a mature mRNA that can be translated into a functional protein.

The splicing process involves the removal of these introns and the joining together of the exons to form a continuous coding sequence. This is typically carried out by a complex known as the spliceosome, which recognizes the boundaries between introns and exons and facilitates their removal. The resulting mature mRNA, which consists only of exons, is then ready for export from the nucleus to the cytoplasm, where it can be translated into a protein.

This processing step is essential because it ensures that the mRNA has the correct coding sequence to produce a functional protein. If introns were not spliced out, the resulting protein would be incomplete or nonfunctional due to the incorrect sequence being translated. Thus, splicing out introns is a critical part of the mRNA processing that enables proper protein synthesis in