Question

Which of the following best describe(s) the function of the 5' mRNA cap?

Answer 1

Answer:

c) It provides a site for ribosome binding in the cytoplasm

d) To protect the transcript from degradation

Explanation:

Transcription is the very first stage of gene expression, which involves the synthesis of a mRNA molecule from a DNA template. The mRNA transcript produced is referred to as a pre-mRNA until it undergoes further processing in the nucleus. This processing makes it matured and ready to be translated (form protein).

The mRNA processing involves three main processes viz: 5' capping, 3' polyadenylation and splicing. The capping of the 5' of the mRNA involves the addition of a 7-methyl guanosine molecule to the 5' of the mRNA molecule. This capping helps protect the mRNA transcript from being degraded by nucleases (digestive enzymes in the nucleus). In addition to this function, the added CAP also provides a recognition site for ribosome to bind to during translation initiation.