The direction of synthesis for a new mRNA molecule is _______ from a _______ template strand.
A) 5'-to-3';5'-to-3'
B) 5'-to-3';3'-to-5'
C) 3'-to-5';5'-to-3'
D) 3'-to-5';3'-to-5'
E) 5'-to-5';3'-to-3'

Question

Quizplus · Accepted Answer

The direction of synthesis for a new mRNA molecule is from 5' to 3', which means that nucleotides are added in a 5' to 3' direction. The template strand, however, is read in the opposite direction, meaning that it is read in a 3' to 5' direction. Therefore, the new mRNA molecule will be synthesized in the opposite direction of the template strand, which is from 5' to 3' (opposite direction), and from 3' to 5' (template strand direction). Choice B correctly shows this directionality.

The Direction of Synthesis for a New MRNA Molecule Is