In which direction is mRNA formed during transcription?

During transcription, mRNA is synthesized in the 5' to 3' direction. This process involves the enzyme RNA polymerase, which reads the template DNA strand from the 3' to 5' direction. As RNA polymerase moves along the DNA, it catalyzes the addition of complementary RNA nucleotides to the growing mRNA strand, which is formed in the 5' to 3' direction. This means that the 5' end of the mRNA is synthesized first while continuing to elongate toward the 3' end. This directionality is essential for proper mRNA processing and translation into protein, as the 5' cap and poly-A tail are added to the respective ends of the mRNA molecule, facilitating its stability and recognition by ribosomes during translation. Understanding this fundamental aspect of molecular biology is crucial for grasping how genes are expressed in living organisms.