UNIT STUDY: Transcription Flashcards
1
Q
What are the differences between DNA and RNA
A
- RNA is single stranded, DNA is double stranded
- RNA has uracil, DNA has tymine
2
Q
What are the 3 types of RNA
A
- rRNA - Part of ribsome, ribosomal protien laced with rRNA, the rest of the organelle is protein
- mRNA (transcription) - messanger RNA
- tRNA (translation) - transfer RNA
3
Q
What is RNA Polymerase do
A
- All the jobs of helicase, primase, DNA polymerase, and ligase
- It can wind and unwind DNA and bind it to the DNA strand without a primer
4
Q
What is initiation
A
- First step of protien synthesis
- Begins at promoter region
- Promoter region has TATA box (lots of adenine and thymine)
5
Q
What is elongation
A
- mRNA strand is being built (5’ to 3’) except for T being switched with U
- Takes place on the template, not coding strand
- Takes place in the nucleas only
6
Q
What is termination
A
- RNA synthesis ends once RNA polymerase reconises a termination sequence
(e.g. AAAA… → UUUU…) - Adenine sequeence doesnt code for anything and there is no need to continue the transcription process
- Nuclear protiens reconize poly uracil (on mRNA) to stop translation
- mRNA strand is relased and RNA polymerase starts once again somethwere else
7
Q
What are post-transcriptional modifications
A
- Must be modified to be protected outside of the nucleas
- Poly-A-tail: 50 to 250 adenine added to 3’ end by poly-A-polymerase
- 5’ cap: 7 guanine added to 5’ end as the starting point for translation
8
Q
What are introns vs exons?
A
- Introns are non coding regions that may interact with protien synetheis
- Introns are only found in eukaryotes
- Introns must be removed by splicomeres
- Exomns are coding regions resonsible for gene expressiol
9
Q
What are splicoemeres and what do they do
A
- Made of small ribonucleoprotiens (snRNP)
- Bind to introns through complimenty bass pairing
- Intron renouvial is precise
10
Q
What happens to introns when they are removed
A
- Intron nucleotides are removed or converted to ATP once they are removed.
