Principles of Molecular Biology: Transcription

These flashcards cover key concepts about transcription, including the process, role of RNA polymerases, differences between prokaryotic and eukaryotic transcription, and post-transcriptional modifications.

What is the Central Dogma of Molecular Biology?

DNA → RNA → Protein

What is transcription in the context of molecular biology?

Transcription is the process by which cellular DNA directs the synthesis of a complementary strand of RNA.

What are the three major types of RNA found in cells?

Messenger RNA (mRNA), Ribosomal RNA (rRNA), and Transfer RNA (tRNA).

What is the difference between bacterial and eukaryotic transcription?

Bacterial transcription is simpler and involves one type of RNA polymerase, while eukaryotic transcription is more complex with multiple RNA polymerases and many regulatory elements.

What is a promoter and its role in transcription?

A promoter is a specific site on DNA where RNA polymerase binds to initiate transcription.

What are the four main steps of transcription?

1. Binding of RNA polymerase to the promoter, 2. Initiation of transcription, 3. Elongation of the RNA chain, 4. Termination of transcription.

What is the function of the sigma factor in bacterial transcription?

The sigma factor helps RNA polymerase to recognize and bind to the promoter for transcription initiation.

What are the three main types of RNA polymerases in eukaryotes and their functions?

RNA Polymerase I synthesizes rRNA, RNA Polymerase II synthesizes mRNA, and RNA Polymerase III synthesizes tRNA and 5S rRNA.

What are the key post-transcriptional modifications that eukaryotic mRNA undergoes?

5' capping, 3' polyadenylation, and splicing.

What is the TATA box and its significance in eukaryotic transcription?

The TATA box is a core promoter element that helps determine the transcription start site.