All there is needed to know about protein synthesis Flashcards
state the start codon
AUG
name the stop codons
UAA
UAG
UGA
what makes up the Prokaryotic large ribosomal subunit?
23 S and 5S (50S)
what makes up the Prokaryotic small ribosomal subunit?
16 S (30S small)
what makes up the 80S Eukaryotes ribosomal subunits?
28S, 5.8S and 5S (60S large) 18 S (40 S small)
what enzyme catalyzes the linkage of the appropriate amino acid to tRNA?
- aminoacyl-tRNA Synthetases
- the attached AA is bound at acceptor stemp
T/F: there are specific aaRS for each amino acids?
very true
where are the identity elements in the tRNA?
-acceptor stem and anticodon loop
Are aminoacyl-tRNA Synthetases able to proofread??
some are!
example: aa-tRNA synthetase for Ile sometimes activates valine.. a separate active site of IleRS has a site specific for Val, but not the larger Ile.
- so if Val is accidentally put on, it will be pulled right back off
the first tRNA binds where at the ribosome??
P site *** all the rest first go to the A site
Prokaryotic Translation:
what is the role of IF-1 in translation?
- blocks A site at beginning of translation
- assists binding of IF-3 to 30 S ribosomal subunit
Prokaryotic Translation:
what is the role of IF-3?
-binds to 30S ribosomal subunit freeing it from 50 S subunit
Prokaryotic Translation:
what does IF-2 do?
-small GTP-binding protein that binds initiator fMet-tRNA and helps it dock with small ribosome subunit
Shine-Dalgarno sequence
The Shine-Dalgarno (SD) Sequence is a ribosomal binding site in bacterial and archaeal messenger RNA, generally located around 8 bases upstream of the start codon AUG. The RNA sequence helps recruit the ribosome to the messenger RNA (mRNA) to initiate protein synthesis by aligning the ribosome with the start codon
