Question

This round of translation functions to detect aberrant transcripts before mass-translation is engaged. In this round of translation, mRNAs are bound with cap-binding complexes. If the mRNA is correct, CBC engages with eIF4E → mass translation ensues.

A) Pioneering Round
B) Initiation Round
C) Elongation Round
D) Termination Round

Answer 1

The Pioneering Round is the initial phase of translation that checks for mRNA integrity, involving cap-binding complexes and eIF4E before moving to mass translation. It is pivotal for preventing the translation of faulty mRNAs.

Step-by-step explanation:

The round of translation described in the question, which involves cap-binding complexes (CBC) and if the mRNA is correct, leads to mass translation, is known as the Pioneering Round of translation. This round is crucial for detecting aberrant transcripts before committing to the full translation process. Once considered correct, CBC engages with eukaryotic initiation factor 4E (eIF4E), which signals the beginning of mass translation. During this process, various initiation factors including eIF-2 and the cap-binding protein, recognize and bind the 5' cap of the mRNA. The mRNA is then scanned for the start codon AUG, following which initiation factors are released, and the large 60S ribosomal subunit binds to the complex, completing the initiation and readying for elongation and termination.