What is the direction of RNA strand synthesis during transcription?

During transcription, RNA strand synthesis occurs in the 5' to 3' direction. This process involves the enzyme RNA polymerase, which synthesizes the RNA by adding nucleotides to the growing RNA strand. The nucleotides are added to the 3' end of the RNA molecule, meaning that for each new nucleotide addition, RNA polymerase works from the 5' to the 3' end.

The DNA template strand that RNA polymerase reads runs in the opposite direction, which is essential as it allows for the proper complementary base pairing. As the enzyme moves along the DNA, it unwinds the double helix and adds complementary RNA nucleotides based on the DNA template. This results in an RNA strand that is synthesized in a 5' to 3' direction, ensuring the correct orientation for future processing and function of the RNA molecule.