DNA Transcription
RNA polymerase unwinds the DNA double helix at the transcription bubble, reads the template strand, and assembles a complementary mRNA molecule one nucleotide at a time. The central dogma of molecular biology, animated.
Transcription Progress
How transcription works
DNA stores genetic information in two complementary strands wound into a double helix. During transcription, the enzyme RNA polymerase binds to a promoter region and begins unwinding the helix, creating a “transcription bubble.”
The polymerase reads the template strand in the 3’ to 5’ direction, assembling a complementary mRNA strand in the 5’ to 3’ direction. The base pairing rules are: A pairs with U (not T — RNA uses uracil), T pairs with A, G pairs with C, and C pairs with G.
Behind the polymerase, the DNA double helix re-anneals. The resulting mRNA strand carries the genetic message to the ribosome for translation into protein.