Transcription Flashcards
1
Q
What are the three differences between DNA and RNA?
A
- RNA is single stranded, DNA is double stranded.
- RNA contains ribose sugar, DNA contains deoxyribose sugar.
- RNA’s fourth base is uracil rather than thymine.
2
Q
How can you identify the 5’ end of a DNA strand?
A
The PO4 end.
3
Q
How can you identify the 3’ end of a DNA strand?
A
The OH end.
4
Q
What structures can RNA form?
A
Primary and secondary.
5
Q
What are the three phases of transcription?
A
- Initiation
- Elongation
- Termination.
6
Q
Describe the initiation phase of transcription.
A
RNA polymerase recognises and binds to a promoter sequence on DNA.
7
Q
Describe the elongation phase of transcription.
A
- RNA polymerase elongated the RNA molecule antiparallel to template DNA.
- Base pairing takes place.
- Ribonucleoside triphosphates are hydrolysed as added.
8
Q
Describe the termination phase of transcription.
A
Special DNA sequences and protein helpers terminate transcription.
•Transcript is released from DNA.
•Primary transcript is called pre-mRNA.
•Pre-mRNA is processed to generate the mature mRNA.
9
Q
Describe the ‘Central Dogma’.
A
DNA ➡️ Transcription ➡️ RNA ➡️ Translation ➡️ Protein.
