chap 12 b

A collection of vocabulary flashcards covering key terms and concepts related to transcription and gene expression.

cis-acting DNA Element

DNA sequences that regulate the transcription of nearby genes.

trans-acting Protein Factor

Proteins that interact with cis-acting elements to regulate gene expression.

Promoter

A DNA sequence that initiates transcription of a gene.

Enhancer

A cis-regulatory element that increases the transcription of associated genes.

Silencer

A cis-regulatory element that decreases the transcription of associated genes.

Insulator

DNA sequences that block the interaction between enhancers and promoters.

Histone Modification

The addition or removal of chemical groups to histone proteins that affect gene expression.

DNA Methylation

The addition of a methyl group to DNA, often suppressing gene expression.

Chromatin

The complex of DNA and proteins that forms chromosomes and regulates gene expression.

Euchromatin

A form of chromatin that is loosely packed and accessible for transcription.

Heterochromatin

A tightly packed form of chromatin that is generally inactive for transcription.

RNA Polymerase II

The enzyme responsible for transcribing protein-coding genes in eukaryotes.

Spliceosome

A complex of proteins and snRNAs that removes introns from pre-mRNA.

Alternative Splicing

The process by which different combinations of exons are joined to produce multiple protein variants from one gene.

MicroRNA (miRNA)

Small, non-coding RNA molecules that regulate gene expression by binding to target mRNA.

XIST

A long non-coding RNA essential for X-chromosome inactivation in mammals.

Transcription Initiation

The first phase of transcription where RNA polymerase binds to the promoter and begins RNA synthesis.

Transcription Elongation

The phase of transcription where the RNA strand is lengthened by RNA polymerase.

Transcription Termination

The process that ends transcription, involving the release of RNA from DNA.