Transcription bubble

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

1. The transcription bubble typically spans about 12-14 base pairs of DNA.
2. It forms when RNA polymerase binds to a promoter and separates the DNA strands.
3. Within the bubble, one strand serves as the template for RNA synthesis.
4. The formation of the transcription bubble requires energy provided by ATP hydrolysis.
5. The size of the transcription bubble remains relatively constant throughout elongation.

Review Questions

• What enzyme is responsible for creating and maintaining the transcription bubble?
• How many base pairs of DNA are typically unwound in a transcription bubble?
• What role does ATP play in the formation of the transcription bubble?

Related terms

RNA Polymerase:

An enzyme that synthesizes RNA from a DNA template.

Promoter:

A DNA sequence that signals RNA polymerase to start transcription.

Template Strand:

The DNA strand that is read by RNA polymerase to synthesize RNA.