Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A transcription bubble is a region of unwound DNA during transcription where RNA polymerase is actively synthesizing RNA. This bubble exposes the template strand, allowing the RNA polymerase to read and transcribe it into RNA.
5 Must Know Facts For Your Next Test
The transcription bubble typically spans about 12-14 base pairs of DNA.
It forms when RNA polymerase binds to a promoter and separates the DNA strands.
Within the bubble, one strand serves as the template for RNA synthesis.
The formation of the transcription bubble requires energy provided by ATP hydrolysis.
The size of the transcription bubble remains relatively constant throughout elongation.