Overview of Transcription

These flashcards cover key concepts and vocabulary related to transcription, including differences from DNA replication, the role of RNA polymerase, and the process of mRNA processing in eukaryotic cells.

Transcription

The process of converting DNA into RNA.

Difference between transcription and DNA replication

Transcription produces a single-stranded RNA molecule, while DNA replication creates an identical copy of DNA.

Location of transcription in prokaryotic cells

Transcription occurs in the cytoplasm.

Location of transcription in eukaryotic cells

Transcription takes place in the nucleus.

Promoter

A DNA sequence that signals the start of transcription and provides a binding site for RNA polymerase.

RNA polymerase

An enzyme that binds to the promoter, synthesizes RNA from the DNA template, and reforms the DNA double helix after transcription.

TATA box

A conserved sequence found upstream of the transcription start site that helps recruit transcription factors.

Direction of RNA synthesis

RNA is synthesized in the 5' to 3' direction.

Difference between RNA transcript and DNA template

RNA contains uracil instead of thymine and is single-stranded.

Termination in prokaryotes

Occurs when RNA polymerase reaches a specific sequence that causes the RNA to detach.

Termination in eukaryotes

Involves a polyadenylation signal that leads to RNA processing.

5’ cap

A modified guanine nucleotide added to the 5’ end of RNA to protect it from degradation.

Poly-A tail

A long sequence of adenines added to the 3’ end of RNA to stabilize it.

Splicing

The process of removing introns and joining exons in pre-mRNA.

Importance of mRNA modifications

They protect RNA from degradation, assist in export from the nucleus, and aid translation efficiency.

Alternative splicing

A process that allows different combinations of exons to be included in the final mRNA, contributing to protein diversity.