Transcription Flashcards
Description of RNA Polymerase action:
Begins transcription without a _____.
Reads the template strand from ___ to ____.
Synthesizes the RNA transcript ___ to ___ using ribonucleotides (NTPs)
Recognizes transcription ______ signals.
Primer
3’ to 5’
5’ to 3’
Termination
Transcription begins with RNA polymerase identifying a gene’s ________.
Promoter region
Transcription ends when a _______ is reached.
Termination signal
By convention, genes are described by the sequence of the ______ strand. However, the _____ strand is actually the strand read during synthesis.
Coding
Template
The DNA coding strand base sequence is identical to the RNA transcript sequence , except _____ has Us instead of Ts.
RNA
Base sequences in DNA are numbered by giving the first base to be transcribed a __ designation with __, __, etc. in the ____ direction.
+1, +2, +3
3’ direction
Downstream means to the _____.
Right, toward 3’ end.
Upstream DNA bases mean to the ____. Toward the _____end.
Left
5’ end
DNA Coding strand is identical to the ______ (except T for U)
mRNA
DNA Template Strand is Complementary and Antiparallel to the ______.
mRNA
Prokaryotic RNA polymerase:
_____+_____=holoenzyme
Core Enzyme + Sigma Factor = Holoenzyme
Prokaryotic RNA Polymerase:
Core Enzyme has ___ subunits (List All) and has _____ activity.
______ is required for recognizing and binding promoter sequences.
4 (2 alpha, 1 beta, 1 beta’)
Sigma Factor
Role of Sigma Factor:
1____
2____
3____
1 - Different sigma factors recognize different types of promoter sequences
2 - Recruits the core enzyme to the DNA Promoter
3 - Dissociates from the core enzyme after transcription begins
Promoters - contain 2 consensus sequences that are recognized by sigma factor:
1___
2___
TATA Box
-35 Sequence
TATA box is sometimes called the _____.
Pribnow box
Prokaryotic RNA Synthesis:
Elongation creates a temporary _____ between the double stranded DNA forming a _______.
Supercoils may be relieved by _____.
Melt
Transcription Bubble
Topoisomerases
Termination of Prokaryotic RNA Synthesis:
Rho-______ termination requires a G-C rich stem loop followed by a poly-U stretch (causes RNA polymerase to dissociate)
Rho-______ termination requires an additional protein (rho factor displaces the DNA template strand from RNA Polymerase)
Independent
Dependent
Prokaryotic mRNAs can be _______.
-i.e., one mRNA can code for several proteins.
Polycystronic
_______ mRNAs are ALWAYS monocistronic
Eukaryotic
Eukaryotic mRNAs are ALWAYS ________.
Monocistronic
This antibiotic binds to prokaryotic RNA polymerase and prevents transcription initiation/elongation and is used to treat tuberculosis.
Rifampin (Rifamycin)
Rifampin (Rifamycin) is an antibiotic that binds to ___________ and prevents __________. It is used to treat _________.
Prokaryotic RNA polymerase
Transcription initiation/elongation
Tuberculosis
Eukaryotic DNA is _______ (chromatin)
-to allow gene transcription the genes must be ‘exposed.’
Highly Condensed
Euchromatin is ______ condensed and more accessible to _______.
Less,RNA polymerases
