EXAM 3 P3 Flashcards
sigma factors
drives expression of genes needed for some particular process by recognizing different promoters
sigma A
housekeeper
sigma N
nitrogen simulation
FiA
flagella synthesis
bacterial transcription
made of a core RNAP plus a sigma factor
-10 and -35 are the recognition sequences
archaeal transcription
single many subunit RNAP
utilizes the TATA site and TATA binding protein
eukaryotic transcription
3 many subunit RNAP
utilizes the TATA site and TBP
gene structure of bacteria
mono or polycistronic
add up to operons and have no introns
gene structure of archaea
mono or polycistronic
no introns
gene structure of eukaryote
only monocistronic and always have introns
characteristics of prokaryotes
little non-coding DNA
no mRNA processing, so it’s ready for translation
transcription and translation are coupled
no nucleus means ribosomes and translation machinery are in the cytoplasm
define coupled transcription and translation
in the cytoplasm
they can happen on the same RNA molecule at the same time
results in very fast production of protein products
only in prokaryotes
characteristics of eukaryotes
lots of non-coding DNA splicing before mRNA can be released into the cytoplasm. transcription is in the nucleus translation is in the cytoplasm no coupling
what is splicing
the first step of mRNA processing. it involves taking the introns out and putting the exons together to forma complete protein coding sequence
other step is adding a 5’ cap on the beginning of mRNA and a poly A tail on the end.
where does splicing occur
in the nucleus