Question

The direction of synthesis of an RNA transcript is _____.

1) 1' –> 5'
2) 5' –> 3'
3) 1' –> 3'
4) 3' –> 5'
5) 2' –> 4'

Answer 1

The direction of RNA synthesis (transcription) is from the 5' to 3' end. This process is facilitated by RNA polymerase which moves along the DNA template strand in the 3' to 5' direction, while adding complementary RNA nucleotides to the growing RNA chain in a 5' to 3' direction.

Step-by-step explanation:

The direction of synthesis of an RNA transcript is 5' –> 3'. RNA synthesis, commonly referred to as transcription, is carried out by the enzyme RNA polymerase, which adds RNA nucleotides in succession to the growing RNA chain in the 5' to 3' direction. This process uses a DNA template strand that is read in the opposite direction, meaning that RNA polymerase moves along the DNA in a 3' to 5' direction. This bi-directional process allows for the base pairing of incoming RNA nucleotides that are complementary to the DNA template strand, leading to the growth of the RNA molecule in a 5' to 3' manner.

It's also important to note that this process happens within the transcription bubble, where the unwinding of DNA allows the RNA polymerase to read the template strand and synthesize RNA. Once completed, the RNA transcript, such as messenger RNA (mRNA), is further processed within the nucleus before it is transported to the cytoplasm for translation into protein.