Transcription Lesson Review Flashcards
(17 cards)
Where does Transcription Occur?
It occurs in the NUCLEUS of EUKARYOTIC cells.
How many strands of DNA are used in any gene to serve as the TEMPLATE STRAND?
Only ONE Strand of DNA.
What is the ENZYME responsible for transcription?
The enzyme responsible is RNA POLYMERASE.
Where does Elongation occur?
It occurs from 5’ to 3’
How many RNA Polymerase does Prokaryotes have?
They only have ONE polymerase.
How many RNA Polymerase does Eukaryotes have?
3 those are:
- RNA Polymerase I (transcribes rRNA).
- RNA Polymerase II (used to make mRNA).
- RNA Polymerase III (makes tRNA).
Where does RNA Polymerase bind to?
It binds “upstream” to the promoter region.
How does a Transcription bubble form?
It forms when RNA polymerase would move along the DNA STRAND as it UNWINDS it.
Where would nucleotides attach?
It would attach in sequences at the 3’ end.
What does DNA do after Transcription?
After transcription DNA would rewind.
When does Transcription end?
It would end when RNA Polymerase reads TERMINATION SEQUENCE on mRNA.
What gets released from the DNA?
mRNA and Polymerase are both released after the Termination stage.
What cell must mRNA be modified in?
They must be modified in EUKARYOTIC Cells and they are the PRIMARY TRANSCRIPT.
What is 7-methyl guanosine and what does it do?
- 5’Cap is added to the beginning.
- Protects from enzymes in cytoplasms
Ribosome recognition.
Where does a POLY-A tail get added?
It gets added to the 3’ end by poly-A polymerase.
What is RNA Splicing?
- It is when splicosomes remove introns (noncoding regions).
- Exons are joined (coding regions) and “exit” the nucleus.
What does it mean if mRNA transcript leaves the NUCLEUS?
- It means that it is ready for translation by ribosomes.
- Introns (remain in nucleus and are degraded or recycled)
