How does the first nucleotide at the 5′ end of a new mRNA chain differ from the other nucleotides in the chain?
A) The first nucleotide is always a uracil.
B) The first nucleotide is always a cytosine.
C) The first nucleotide retains its triphosphate group, while the others do not.
D) The first nucleotide does not retain its triphosphate group, while the others in the chain do.
E) The first nucleotide is always a modified cytosine.

Question

Quizplus · Accepted Answer

The first nucleotide at the 5′ end of a new mRNA chain retains its triphosphate group, which is a unique feature distinguishing it from the other nucleotides in the chain that only retain one phosphate group following their incorporation into the growing RNA strand. This triphosphate group is important for the initial steps of mRNA synthesis and processing.

How Does the First Nucleotide at the 5′ End of a New