What are the changes called that occur to a newly transcribed mRNA before it is translated into a protein?

The changes that occur to a newly transcribed mRNA before translation is referred to as post-transcriptional modification. This process is essential for the maturation of mRNA and includes several key steps that prepare the mRNA for successful translation into a protein.

During post-transcriptional modification, the primary RNA transcript undergoes capping, polyadenylation, and splicing. The addition of a 5' cap protects the mRNA from degradation and assists in ribosome binding during translation. The addition of a poly-A tail at the 3' end also serves protective functions and facilitates the export of the mRNA from the nucleus to the cytoplasm. Splicing removes introns—non-coding regions of the RNA—and joins together exons, which are the coding sequences. This results in a mature mRNA that accurately represents the genetic information needed for protein synthesis and ensures the correct expression of genes.

While RNA splicing is indeed a component of the post-transcriptional modifications, it does not encompass the entire process. Post-translational modification refers to changes that occur to a protein after it has been synthesized, and RNA editing involves alterations to the nucleotide sequence of the RNA itself. Therefore, the choice that best describes all the changes that occur