module 7 lec 4 Flashcards
What happens to mRNA after transcription in eukaryotes?
It is processed before translation.
What is added to the 5’ end of mRNA in eukaryotes?
A methylated cap is added.
What is the purpose of the 5’ methylated cap?
It protects mRNA from degradation and helps with translation initiation.
How does the 5’ cap affect mRNA stability?
The 5’ cap increases mRNA stability and facilitates export from the nucleus.
What is added to the 3’ end of mRNA in eukaryotes?
A polyA tail is added.
What is the function of the polyA tail?
It stabilizes the mRNA, aids in export from the nucleus, and helps with translation initiation.
How does the polyA tail affect mRNA?
The polyA tail protects mRNA from degradation and enhances translation efficiency.
What happens to mRNA after the polyA tail is added?
The mRNA is ready for export to the cytoplasm for translation
What is RNA splicing?
RNA splicing removes introns from the pre-mRNA, leaving only exons.
What are exons?
Exons are the coding sequences in a gene’s DNA and mature mRNA.
What are introns?
ntrons are non-coding sequences found in DNA but not in mRNA.
Why are introns removed during RNA splicing?
Introns are removed to produce a functional mRNA that can be translated into protein.
Do all eukaryotic genes have introns?
No, but some eukaryotic genes have many introns
What happens to exons after RNA splicing?
Exons are joined together to form the final mRNA.
What is RNA splicing?
RNA splicing is the process of removing introns from pre-mRNA and joining the exons together.
Why is RNA splicing important
It converts pre-mRNA into a mature mRNA that can be translated into protein.
What are introns?
Introns are non-coding sequences that are removed during RNA splicing.
What are exons?
Exons are coding sequences that remain in the mRNA after RNA splicing.
How does RNA splicing affect pre-mRNA?
RNA splicing removes introns and connects the remaining exons to form mature mRNA.
What are spliceosomes?
Spliceosomes are complexes of proteins and RNA that carry out RNA splicing.
Can RNA splicing vary between different cell types?
Yes, alternative RNA splicing can produce different mRNA variants from the same gene
What is alternative splicing?
Alternative splicing is when different combinations of exons are joined, producing multiple mRNA forms from a single gene.
What happens to introns after RNA splicing?
Introns are degraded after being removed from pre-mRNA during RNA splicing.
How are introns degraded after RNA splicing?
Introns are typically degraded by cellular exonucleases and RNA degradation pathways.
Why is the degradation of introns important?
Degrading introns helps prevent the accumulation of non-coding RNA and ensures efficient use of cellular resources.
What catalyzes RNA splicing?
Spliceosomes catalyze RNA splicing.
What are spliceosomes?
: Spliceosomes are complexes of proteins and RNA that perform RNA splicing.
What are ribozymes?
Ribozymes are RNA molecules that function as enzymes, facilitating RNA splicing.
Why are ribozymes important in RNA splicing?
Ribozymes help catalyze the splicing reactions, ensuring they occur correctly and efficiently.
What does RNA splicing ensure?
RNA splicing ensures that all splicing reactions occur in a coordinated and precise manner.
What is alternative splicing?
Alternative splicing allows different mRNAs to be produced from the same pre-mRNA transcript.
How does alternative splicing contribute to gene diversity?
It enables a single gene to produce multiple protein variants by combining different exons in various ways.
What are transplicing events?
Transplicing combines exons from different genes to form a new mRNA.
How are transplicing events different from alternative splicing?
Transplicing combines exons from separate genes, while alternative splicing rearranges exons within a single gene.
What is the benefit of alternative splicing?
It increases the diversity of proteins that can be produced from a single gene, contributing to complexity in eukaryotic organisms.
