DNA Transcription Study Guide

This set of flashcards covers key concepts, processes, and mechanisms related to DNA transcription, which is essential for understanding gene expression.

What is the process of transcription in DNA?

Transcription is the process by which an RNA molecule is synthesized using a DNA template.

What enzyme is responsible for synthesizing RNA during transcription?

RNA polymerase.

In which direction does RNA polymerase synthesize RNA?

RNA is synthesized in the 5′→3′ direction.

What are the two types of termination mechanisms in prokaryotic transcription?

Rho-dependent and Rho-independent termination.

What is the role of the sigma (σ) factor in prokaryotic transcription?

The σ factor enables promoter recognition and forms the holoenzyme.

What elements make up the core promoter in eukaryotic transcription?

The core promoter includes the TATA box and other sequences located about 25 bp upstream.

What is the function of TFIID in the transcription process?

TFIID recognizes the TATA box and recruits TFIIB.

What happens during RNA capping?

A 7-methylguanosine cap is added to the 5′ end of the RNA for protection, ribosome binding, and nuclear export.

What role does the polyadenylation signal AAUAAA have in transcription?

It signals the addition of a poly-A tail at the 3′ end of the RNA.

What is alternative splicing?

Alternative splicing allows one gene to produce multiple protein isoforms by removing certain exons and joining others.

What is the significance of the CTD in RNA polymerase II?

The C-terminal domain (CTD) coordinates transcription with RNA processing and maturation.

What is RNA editing?

Post-transcriptional nucleotide modification, such as A→I or C→U changes.

What is one disease related to splicing errors?

Spinal Muscular Atrophy (SMA).

How does transcriptional regulation integrate with mRNA processing?

Transcriptional regulation is coupled with mRNA processing, export, and translation.

What example of RNA editing is associated with the ApoB gene?

In the liver, the ApoB gene produces ApoB-100; in the intestine, it produces ApoB-48 via C→U editing.