Difference Between Introns and Exons
Eukaryotes have evolved their genome and have made it more complex by introducing the coding regions (EXON) and the non-coding region (INTRON). The stretch of DNA contains both the introns and the exons, in which exons participate in the translational process (the process of protein formation). In contrast, the introns are the noncoding intervening spacer sequences which are removed further during the RNA processing.
Exons
Exons also called expressing sequences, are the mRNA sequences that get joined during the post-transcriptional modification and code for amino acid sequencing during translation.
Do prokaryotes have exon sequences?
The prokaryotic genome is not as complex as eukaryotes. So, the whole genome of prokaryotic organisms contains only the exon sequences, and no intron sequences can be seen in prokaryotes except a few exceptions.
Introns
Introns are the intervening sequences in the eukaryotic genome between the exon sequences. They do not code for any protein sequences of amino acid sequences as they are removed during the post-transcriptional modifications (occur inside the nucleus).
- The mRNA transcribed during the process of transcription (a process in which the RNA is formed by taking DNA as a template strand) is a premature RNA (called hnRNA ) that undergoes various post-transcriptional modifications to form a mature RNA (mRNA).
- One of the post-transcriptional events is intron splicing, or the removal of intron sequencing to form a mature RNA.
- The introns can be removed by forming a spliceosome complex, or some of the introns have an inbuilt mechanism of removing self from the exons sequence (called self-splicing introns).
- Introns are present in a range of RNAs irrespective of the fact whether they are coding or non-coding introns RNAs; for example, introns are present in mRNA, rRNA, and tRNA.
Introns could be self-splicing or non-self-splicing
Non-self-splicing introns are the introns found in most RNA molecules, and the spliceosome complexes remove them. Whereas the self-splicing introns found in rRNA have the ability to remove them by an intrinsic ability of transesterification reaction.
Difference Between Introns and Exons
Difference Between Introns and Exons: Introns and Exons are the integrated part of the eukaryotic genome. Introns are intervening non-coding nucleotide sequences whereas the exons are the amino acid coding sequences.
We have seen various evolutionary changes from the prokaryotes to the eukaryotes. The eukaryotic cells have become more advanced and organised as compared to prokaryotes. Although prokaryotes have a higher tendency to evolve faster than eukaryotes, but the level of complexity in a eukaryotic cell is unmatchable.
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