Chapter 7: Transcription

Flashcards summarizing key terms and concepts from Chapter 7 on Transcription.

Transcription

The first step in gene expression where a gene makes a product that is useful to the cell by directing the synthesis of RNA.

Gene Expression

The process by which a gene makes a product that is useful to the cell or organism.

RNA Polymerase

An enzyme that transcribes RNA from a DNA template.

Promoter

A DNA sequence that attracts RNA polymerase and signals the start of transcription.

Terminator

A DNA sequence that signals the end of transcription and causes RNA polymerase to release the transcript.

Exons

Coding segments of DNA that are expressed in the final mRNA.

Introns

Noncoding segments of DNA located within a gene that are removed during RNA splicing.

mRNA (Messenger RNA)

RNA that codes for proteins and carries genetic information from DNA to ribosomes.

rRNA (Ribosomal RNA)

Forms the core of the ribosome structure and catalyzes protein synthesis.

tRNA (Transfer RNA)

Adaptors between mRNA and amino acids during protein synthesis.

RNA Processing

Modifications of RNA after transcription, including capping, polyadenylation, and splicing.

Capping

The addition of a methylated Guanine cap at the 5’ end of mRNA to increase stability.

Polyadenylation

The addition of a poly-A tail at the 3’ end of mRNA to increase stability and facilitate export.

RNA Splicing

The process of removing introns from the pre-mRNA and joining exons together.

Lariats

The excised introns that form loop structures during the splicing process.

Sigma Factor

A protein that helps RNA polymerase to recognize promoter sites in prokaryotic transcription.

General Transcription Factors

Proteins required to initiate transcription in eukaryotes by positioning RNA polymerase at the promoter site.

Nucleosomes

Structural units of DNA packaging that can affect RNA polymerase function during transcription.

Eukaryotic Promoter

Contains specific sequences like TATA box which are essential for the recruitment of transcription factors.

RNA Transcript

The complementary RNA strand synthesized from the DNA template during transcription.