Key points:

Transcription is the process in which a gene's DNA sequence is copied (transcribed) to make an RNA molecule.

RNA polymerase is the main transcription enzyme.

Transcription begins when RNA polymerase binds to a promoter sequence near the beginning of a gene (directly or through helper proteins).

RNA polymerase uses one of the DNA strands (the template strand) as a template to make a new, complementary RNA molecule.

Transcription ends in a process called termination. Termination depends on sequences in the RNA, which signal that the transcript is finished.

RNA polymerase is crucial because it carries out transcription, the process of copying DNA (deoxyribonucleic acid, the genetic material) into RNA (ribonucleic acid, a similar but more short-lived molecule).

Transcription is an essential step in using the information from genes in our DNA to make proteins. Proteins are the key molecules that give cells structure and keep them running. Blocking transcription with mushroom toxin causes liver failure and death, because no new RNAs—and thus, no new proteins—can be made.^22squared

Transcription is essential to life, and understanding how it works is important to human health. Let's take a closer look at what happens during transcription