Question

MRNA surveillance mechanisms are necessary ________.

A) to recruit general transcription factors to the promoter
B) in determining which alternative splice site should be used
C) to eliminate mRNAs with a premature stop codon
D) for polyadenylation at the 3' end of mRNA
E) to measure the concentration of mRNAs in the cytoplasm

Answer 1

mRNA surveillance mechanisms are crucial for eliminating mRNAs with premature stop codons to ensure the translation of fully functional proteins. These mechanisms contribute to the stability and quality control of the mRNA population in the cytoplasm, which in turn impacts protein synthesis.

Step-by-step explanation:

mRNA surveillance mechanisms are necessary to eliminate mRNAs with a premature stop codon.

This function helps to maintain the quality of the mRNA population within the cell and prevent the translation of potentially deleterious truncated proteins. mRNA surveillance is a critical aspect of post-transcriptional regulation.

Messenger RNA (mRNA) undergoes several processing steps including 5' capping, 3' polyadenylation, and splicing.

The 5' cap and poly-A tail are essential for mRNA stability and translation, as they protect the mRNA from degradation and are recognized by factors involved in guiding ribosomes to initiate translation.

Spliceosomes are responsible for removing non-coding introns from the pre-mRNA, a process that can result in different proteins being produced from the same mRNA transcript due to alternative splicing.