Transcription 101: The Big Picture
State the overall purpose of transcription within the central dogma of molecular biology.
To synthesize mRNA that carries genetic information from DNA to ribosomes for Protein production.
Which DNA strand provides the sequence that RNA Polymerase makes a complementary RNA strand to?
Template Strand (Noncoding Strand)
What stage of transcription does RNA Polymerase bind to DNA?
Initiation
What do you call the DNA region that dictates where transcription should begin?
Promoter
Name the enzyme responsible for synthesizing mRNA in eukaryotes.
RNA Polymerase II
Which DNA strand has nearly the same nucleotide sequence as the mRNA produced during transcription?
Coding Strand (Nontemplate)
What happens to the DNA strand when transcription begins?
The double helix unwinds and forms a transcription bubble that exposes the template strand for RNA synthesis.
What is the purpose/importance of the TATA box in transcription initiation?
This is the binding site for the TBP (TATA Binding Protein) and helps correctly position RNA Polymerase at TSS (Transcription Start Site).
Why can transcription factors function as both activators and repressors.
Transcription factors bind to promoter and enhancer regions to initiate or prevent transcription and ensure genes are expressed only when needed.
RNA Polymerase adds nucleotides to the 3' end of the newly synthesized RNA, building 5' to 3' while reading off the template 3' to 5'.
If a coding strand reads 5' ATGCCTTGA 3', what would be the corresponding mRNA sequence?
5' UCAAGGCAU 3'
Explain what has to happen to assemble the transcription initiation complex.
1. Transcription factors bind to the promoter and TATA Box
2. TBP attaches to the TATA box, allowing RNA Polymerase to bind to the promoter, which lets DNA unwind.
Identify the 2 other types of RNA (excluding mRNA) that RNA Polymerase can synthesize.
snRNA and microRNA