The Control of Gene Expression

Gene expression is regulated at multiple stages: transcriptional, post-transcriptional, translational, and post-translational. Transcriptional regulation involves transcription factors controlling RNA synthesis. Post-transcriptional regulation includes RNA binding proteins affecting RNA stability and export. Translational regulation occurs at the ribosome level, affecting mRNA translation into proteins. Post-translational regulation involves protein modifications that alter cellular functions.

What role do transcription factors play in gene expression?

• They modify proteins after translation.

• They transport proteins out of the cell.

• They bind to DNA to regulate transcription.

• They degrade RNA molecules.

How does a repressor molecule affect gene transcription?

• It increases the stability of RNA.

• It facilitates the export of RNA from the nucleus.

• It prevents RNA polymerase from transcribing the gene.

• It enhances the binding of RNA polymerase.

What is the primary function of RNA binding proteins in post-transcriptional regulation?

• To initiate DNA replication.

• To influence RNA stability and export.

• To assemble ribosomal subunits.

• To modify proteins chemically.

In translational regulation, what do certain molecules interfere with?

• The chemical modification of proteins.

• The binding of transcription factors to DNA.

• The stability of RNA molecules.

• The binding of ribosomal subunits.

What is a common method of post-translational regulation?

• Exporting RNA from the nucleus.

• Breaking down or chemically altering proteins.

• Binding RNA to ribosomes.

• Transcribing DNA into RNA.