Transcription

Transcription

is the process of copying a gene’s DNA sequence into RNA

Transcription

It’s the first step of gene expression, turning genetic information into a message that can eventually be used to make proteins.

Transcription

• In eukaryotes, it happens in the nucleus, while translation occurs in the cytoplasm.

Transcription

is the bridge between DNA (information storage) and translation (functional proteins).

Transcription

• When: Throughout interphase, whenever a gene is expressed.

• Where: Nucleus.

Initiation

• RNA polymerase binds to the promoter region with help from transcription factors.

• DNA strands separate.

Elongation

RNA polymerase builds a single-stranded RNA transcript complementary to the DNA template strand (U pairs with A).

Termination

RNA polymerase reaches a terminator sequence and detaches.

RNA Processing

• 5′ cap added (protection + ribosome attachment).

• Poly-A tail added (stability).

• Introns (noncoding) removed; exons (coding) spliced together.

Transcription

Outcome: A mature mRNA that carries the genetic code from DNA to the cytoplasm.

Transcription

From DNA to RNA