Final answer:
The function not related to the 5' cap and 3' poly-A tail of an mRNA molecule is initiating translation. Correct option is (C).
Step-by-step explanation:
Among the listed options for the functions of the 5' cap and 3' poly-A tail of a mature eukaryotic mRNA molecule, the one that is not a function is splicing introns (option D). The 5' cap and 3' poly-A tail have multiple roles:
- The 5' methyl guanosine cap aids in the export of mRNA from the nucleus to the cytoplasm, prevents mRNA degradation, and is recognized by factors involved in protein synthesis to help initiate translation.
- The 3' poly-A tail also assists in mRNA nuclear export, increases mRNA stability in the cytoplasm, and has a regulatory role in the half-life of mRNAs.
However, splicing introns is a separate process that occurs prior to the addition of these structures. The correct answer to the question is that the function not associated with the 5' cap and 3' poly-A tail is initiating translation (option C).
They facilitate mRNA export from the nucleus, enhance mRNA stability by protecting the mRNA from degradation, and aid in initiating translation by ribosomes. However, they do not have a role in splicing introns. Splicing is a process that occurs during mRNA processing and involves the removal of introns and joining of exons to produce a mature mRNA molecule.