CELS191 Molecular Biology & Genetics Lecture 11: Gene Expression - Transcription

These flashcards cover key concepts from the lecture on gene expression and transcription, designed to help with exam preparation.

What is the Central Dogma of Molecular Biology?

It describes the flow of genetic information from DNA to RNA to protein.

What is Gene Expression?

The process by which information from a gene is used in the synthesis of a functional gene product, such as a protein or non-coding RNA.

Which enzyme catalyzes the transcription process?

RNA polymerase.

What is the template strand in transcription?

The DNA strand that RNA polymerase uses to synthesize mRNA.

What are the three stages of transcription?

Initiation, Elongation, Termination.

What region of DNA signifies the beginning of transcription?

The promoter region.

What is the difference between coding and template strands in DNA?

The coding strand has the same sequence as the mRNA (except for T vs U), while the template strand is complementary to the mRNA.

What does RNA polymerase II do during transcription?

It synthesizes mRNA from the template strand and does not require a primer.

What are UTRs in a gene structure?

Untranslated regions that are transcribed but typically not translated, influencing gene expression.

What role does the 5' G cap play in mRNA processing?

It prevents mRNA degradation, promotes intron excision, and provides a binding site for ribosomes.

What are non-coding RNA molecules?

RNA molecules that do not code for proteins but have other functions, such as tRNA.

What is the significance of non-coding DNA regions?

They can be transcribed but not translated and are involved in regulating gene expression.

Why is it important for RNA polymerase to have primase activity?

So it can initiate RNA synthesis by forming the first phosphodiester bond without a pre-existing strand.

What happens during the elongation phase of transcription?

RNA polymerase adds nucleotides to the growing mRNA strand complementary to the DNA template.

What could be the consequence of mutations in non-coding DNA sequences?

They may disrupt normal gene expression.

What is the role of topoisomerase II in transcription?

It releases supercoiling tension that builds up ahead of RNA polymerase.