3.2

Transcription

The process of copying genetic information from DNA to RNA, occurring in the nucleus.

RNA polymerase 2

The enzyme responsible for synthesizing mRNA during transcription.

Initiation stage

The first stage of transcription where proteins gather at the promoter region and form the transcription initiation complex.

TATA-binding protein (TBP)

A protein that marks the start site for transcription.

Elongation stage

The stage of transcription where RNA polymerase synthesizes RNA in the 5’ to 3’ direction.

Termination stage

The final stage of transcription where RNA polymerase reaches a termination signal and releases the RNA transcript.

5' Cap

A modified guanine nucleotide added to the beginning of pre-mRNA for protection and ribosome recognition.

3' Poly A Tail

A stretch of adenine bases added to the end of pre-mRNA to enhance its stability.

Introns

Non-coding regions removed from pre-mRNA during processing.

Exons

Coding regions of pre-mRNA that are joined together during processing.

Alternative splicing

The process that allows a single gene to produce multiple protein variants by joining exons in different combinations.

Mature mRNA

The processed form of mRNA that exits the nucleus for translation.