2 Flashcards
What is the role of RNA polymerase in transcription?
RNA polymerase synthesizes RNA from a DNA template without requiring a primer. It reads the template strand to form a complementary RNA strand.
What are the differences between the coding and template DNA strands?
The coding strand has the same sequence as the RNA transcript (except T is replaced with U), while the template strand is read by RNA polymerase.
What is the direction of RNA synthesis?
RNA is synthesized in the 5’ to 3’ direction.
What is the role of the sigma (σ) factor in prokaryotic RNA polymerase?
The sigma (σ) factor helps RNA polymerase recognize and bind to the promoter region, initiating transcription in prokaryotes.
What are the key differences between prokaryotic and eukaryotic transcription?
Prokaryotic transcription is coupled with translation and lacks modifications, while eukaryotic transcription includes mRNA processing and occurs in the nucleus.
What modifications occur to eukaryotic mRNA before translation?
Eukaryotic mRNA undergoes capping at the 5’ end, addition of a poly(A) tail at the 3’ end, and splicing to remove introns.
What is the significance of the AAUAAA sequence in eukaryotic RNA?
The AAUAAA sequence near the 3’ end signals for mRNA cleavage and polyadenylation.
What is RNA splicing, and why is it important?
RNA splicing removes introns from the primary transcript to produce a functional mRNA ready for translation.
What are the roles of exons and introns in RNA processing?
Exons are coding sequences that remain in the final mRNA, while introns are non-coding sequences that are spliced out.
What is alternative splicing, and what is its function?
Alternative splicing allows a single gene to produce multiple protein variants, depending on the developmental stage or tissue type.
