Flashcards in Kandpal - Transcription Deck (34):
What are the structural differences between RNA and DNA?
RNA is mostly single stranded, ribose, uracil
DNA is double stranded, deoxyribose, thymine
List the different RNAs from least abundant to most.
mRNA, tRNA, and rRNA
List 4 functions of RNA.
Genome, information carrier, protein synthesis, and as a catalyst.
What is an example of RNA as a genome?
How is RNA involved in protein synthesis?
As rRNA and tRNA
Name an example of a catalytic RNA.
What carbon is different between ribose and deoxyribose?
Where is mRNA located?
nucleus and cytoplasm
Where is tRNA located?
Where is rRNA located?
ribozymes and nucleus
How many subunits does RNA polymerase in E. coli have?
What part of the RNA polymerase recognizes the promoter sequence?
the sigma subunit recognizes the promoter sequence
What does tight binding of the promoter with the promoter sequence lead to?
opening of the DNA
What is strength of binding and speed of binding dependent on?
It is dependent on the promoter sequence
What occurs if the promoter sequence is closely related to the sigma subunit?
The bond forms faster and it is a stronger/tighter bond
What are known as consensus sequences?
the short conserved sequences of the promoter sequence
What is the -35 consensus sequence?
35 bases upstream of the start site; varies from 16-19 base pairs
What is the -10 consensus sequence?
10 bases upstream of the start point; varies from 5-9 base pairs
What is the starting point referred to?
How many RNA polymerases do eukaryotes have and how many do bacteria have?
Eukaryotes have 3 and bacteria only has one.
How does eukaryotic RNA polymerase bind to promoter?
Binds indirectly by contacting promoter sequences via transcription factors
Between eukaryotes and bacteria which uses operons?
Which genes are individually regulated bacteria or eukaryotic?
Which bacterial polymerase directly binds the promoter sequence?
the bacterial RNA polymerase holoenzyme that contains the sigma subunit
How can bacterial and eukaryotic RNA polymerases be distinguished?
By their susceptibilities to two inhibitors: rifampin (bacterial) and alpha-amanitin (eukaryotic)
How does rifampin inhibit bacterial RNA polymerase?
it binds to the beta subunit and blocks the path of nascent RNA
How does alpha-amanitin inhibit eukaryotic RNA polymerase?
binds to and inactivates the largest subunit of RNA polymerase II, RPB1
What blocks transcription in both bacterial and eukaryotic polymerases?
actinomycin-D prevents transcription in both by binding to DNA
What kind of antibiotic is Rifampicin?
broad-spectrum antibiotic used for mycobacterial infections (pts w/TB and immunosuppressed pts)
What is a point of concern with rifampicin antibiotics?
point mutation in bacterial beta subunit changes rifampin binding site and does not allow it to bind
What type of antibiotic is Ciprofloxacin?
A quinolone antibiotic
How does quinolone work?
binds to the A subunit of bacterial DNA gyrase and impairs DNA cleavage and resealing activity = DNA damage
What type of antibiotic is Novobiocin?
A coumarin antibiotic