DNA transcription Flashcards
What is transcription?
Reading the DNA sequence and making RNA from the information
- enzymatic synthesis of RNA from a DNA template and forms the first step in gene expression
Transcription is the generation of a ______ ____ (____)
messenger RNA (mRNA)
What is translation?
The enzymatic synthesis of protein from a transcribed gene sequence into a functional RNA molecule mRNA
Transcription is _____ by an RNA _____ enzyme complex which requires:
- a ____ template
- _______ (ATP, GTP, CTP & UTP)
catalysed
polymerase
dsDNA
ribonucleotides
RNA synthesis is in the __ to __ direction
5’
3’
What does the sense strand do?
carries the gene sequence that will be copied into an RNA molecule that will be later translated into protein
What does the antisense strand do?
- used as a template to generate a copy of the sense strand through complementary base airing.
- also carries the gene sequence for RNA molecules that are usually non-coding and function as structural/regulatory molecules
In ______ there is a _____ _____ _____
prokaryotes
single RNA polymerase
How many RNA polymerase enzymes are there in eukaryotes?
3 - I, II and III
List what each polymerase is responsible for transcribing different RNAs
I - transcribes most rRNA (ribosomal RNAs)
II - responsible for transcription of all-protein coding genes
III - transcribes tRNAs (transfer RNAs)
What does initiation of transcription involve?
The binding of RNA polymerase complex to the dsDNA
_____ can be switched on ____ or ____ based on the ______ elements present and if they are ______ by bound proteins
Promoters
weakly or strongly
sequence
stimulated
The dsDNA needs to be locally _____ for the RNA polymerase to access the ____ _____
unwound
promoter sequence
What is the site of action known as for when the polymerase starts to synthesise the mRNA at a specific nucleotide?
start site/initiation site
In elongation, the polymerase is moving in the 3’ to 5’ direction along what strand?
antisense/template DNA strand
