Transcription Flashcards
(10 cards)
How does the flow of information work in cell replication
DNA (DNA replicated) -> RNA (transcription) -> Protein
Central Dogma process
1) Transcription
DNA -> pre-mRNA (RNA polymerase)
Copy genetic code -> compl RNA
2) Processing
pre-mRNA spliced, exons join
5’ cap and poly-A tail = stabilise mRNA
3) Translation (protein synthesis)
-Mature mRNA enter cytop attach to ribosome
-tRNA brings specific amino acids to codons on mRNA
-RIbosome form polypeptide chain
how does RNA differ from DNA
1) RNA single stranded
2) RNA is ribose not deoxyribose
3) RNA has uracil not thymine
what is the polarity of DNA
top: 5’ - to - 3’
Bottom: 3’ – to – 5’
5’-PO4 and 3’-OH groups
Transcription has three phases
initiation
elongation
termination
What does initiation do
RNA polymerase binds to promoter region
exposed template strand
What happens during the elongation stage of transcription
-RNA polymerase builds RNA in 5’ to 3’ direction
-Adds RNA nucleotides to comp strand using temp strand
-Ribonucleoside triphosphates (NTPs) are used
-ribonucleotide triphosphate hydrolyzed -> energy for RNA synthesis
What does termination do
transcription continues until RNA polymerase reaches termination sequence
pre-mRNA detaches and undergoes processing to form mRNA
what happens to RNA after dna template
rna transcribed from DNA template, bases are exposed by unwinding double helix
what changes about the DNA strand during elongation
One side os RNA the other is DNA
contains uracil