MGD9+10 Flashcards
What is the shorthand for the substrates of DNA polymerase?
dNTPs
What is the shorthand for substrates for RNA polymerase?
NTPs
What do transcription factors do?
They recognised certain sequences of DNA and bind to them. They determine the direction of transcription.
Where in the sequence does transcription start?
1bp after RNA polymerase binds.
What is the promoter for eukaryotes and where is it located?
TATA box
Located at -30
What is the promoter for prokaryotes and where is it located?
Pribnow box
Located at -10
What is the open reading frame?
The part of the mRNA that is translated.
At which end does capping of mRNA occur?
5’ end
At which end does polyadenylation of mRNA occur?
3’ end
Which RNA polymerase makes rRNA?
RNA polymerase I
Which RNA polymerase makes mRNA?
RNA polymerase II
Which RNA polymerase makes tRNA?
RNA polymerase III
What kind of ribosomes do prokaryotes have and what subunits make up it?
70S
Subunits = 30S and 50S
What kind of ribosomes do eukaryotes have and what subunits make it up?
80S ribosomes
Subunits: 40S and 60S
In which direction is a protein translated?
N -> C
Name the features of the genetic code
triplets, non-overlapping and degenerate
What is the start codon?
AUG
What are the stop codons?
UAA
UGA
UAG
What do you call an activated tRNA?
Amino acyl tRNA
What is the aspecific base?
Inosine
What is the wobble position?
The 3rd position in the codon
What can inosine bond with?
C, U and A
What does tRNA synthetase do?
It recognises specific anticodons and adds the correct amino acid to the tRNA to create an amino acyl tRNA.
Which subunit of the ribosome binds first?
The smaller subunit
Eg. 40S
What is translocation?
The movement of the ribosome along the mRNA during translation.
What are the 2 sites in a ribosome called and what do they do?
P site - holds the growing peptide chain
A site - accepts the tRNA to allow a new amino acid to bind
Which enzyme is required to from the peptide bonds in translation?
Peptidyl Transferase
What is required for translation termination?
water and a stop codon
What is a polysome?
A strand of mRNA with many ribosomes attached to it
How do bacteria differ in terms of transcription and translation?
They have: simpler promoters, different transcription and translation factors, only one type of RNA polymerase, coupled transcription and translation, no post-transcriptional processing, shorter lived mRNAs and simpler ribosomes.
