Transcription Flashcards
mRNA function
Encodes for amino acids sequence of a polypeptide
Four main types of RNA
Messenger
Transfer
Ribosomal
Small nuclear
mRNA
tRNA
rRNA
Snrna
tRNA function
Brings amino acids to ribosomes during translation
rRNA function
With ribosomal proteins, makes up the ribosomes, the organelles that translate mRNA
snRNA function
With proteins, forms complexes used in RNA processing in eukaryotes
Makes snRNP that makes spliceosomes that take out introns
During transcription, template strand is read from
3’ to 5’
During transcription, RNA is transcribed in which direction
5’ to 3’
In prokaryotes transcription and translation are
—-
Coupled
What does it mean to couple transcription and translation
Translation begins while Transcription is still happening
What formation tAkea out introns
Spliceosomes
Do prokaryotes or eukaryotes synthesize mRNA with RNA polymerase?
Both do
Prokaryotic mRNA vs eukaryotic mRNA
Prokaryotic: not processed- the transcript is the actual molecule that is translated (colinear)
Eukaryotic mRNA is processed first
Processing mRNA
Introns are removed by RNA splicing
5’ caps and 3’ poly A tails are added
RNA splicing
snRNP Forms a spliceosome that bends intron into lariat shape and then splices it off
Promoter function
Site where transcription machinery binds to initiate transcription. 2 DNA strands are separated there and RNA polymerase begins transcription process
What would a mutation in intron section of gene do?
No effect since it is taken out anyways
Promoter region
Where the start of transcription happens. The RNA polymerase attaches here before it starts transcribing
Tata box
Region in promoter region where transcription initiation happens
Terminator sequence
Signals Where transcription ends
Initiation
RNA polymerase and transcription factors bind to promoter region on DNA and unzips (10-20 nucleotides at a time)
Elongation
RNA polymerase reads DNA template in 3 to 5 direction and creates mRNA strand in 5 to 3 direction
Termination
When RNA polymerase reaches the termination sequence, it stops copying DNA. And mRNA is released
Transcription happens in the
Nucleus
Transcription factors
Help enzyme recognize promoter region
