Translation test 1 Flashcards
(30 cards)
Translation goal
make structural protein using mRNA as template
only one codon
AUG and UGG
stop codons
UAA UAG UGA
tRNA structure and function
brings amino acids in
clover shape/ secondary structure
Function: carry appropriate AA into ribosome to add to polypeptide chain
tRNA: eukaryotes vs prokaryotes
eukaryotes has more
Acceptor stem
right before 3’ end, ACCA for all AA
Aminoacyl tRNA (AARS)
covalently links amino acid to tRNA
ester bond/ covalent
Anticodons
aligns with codon (antiparallel)
still need to read code 5’->3’ for figuring out name
wobble
tRNA anticodon with mRNA codon
doesn’t always follow char gaff’s rule for base pairing (BUT ONLY FOR LAST BASE IN CODON/ 5’ IN ANTICODON)
wobble base pairs
5’ Anticodon base:
C and A= normal
U= AG
G= UC
I= UCA
reading frames
where you start
only 3 possible (look for start codon)
Ribosome structure (prokaryotes)
30S 50S 70S
not additive
pro= odd
Ribosome structure Eukaryotes
40S 60S 80S
Euk = Even (EEEEE)
Places tRNA and mRNA interact in ribosome
A site
P site
E site
A site
binds to A-tRNA aminoacyl-tRNA
P Site
binds tRNA with growing peptide chain
E Site
Exit E-tRNA
Empty move to Exit (EEE)
HC=O
modification of meth so this= 1st tRNA in initiation
Shine-Dalgaro sequence
sequence in mRNA that helps align sequence with small ribosomal subunit
prokaryotic only
ribosomal binding site 8 upstream
translation initiation
look at slide 28 to understand how a p and e site work
eukaryotic translation initiation
40S subunit scans DNA circularly until it finds start site
Translation Factors IF-2
delivers initiator tRNA to P site of ribosome
Translation factor EF-Tu
delivers aminoacyl-tRNA to A site of ribosome during elongation
translation factor EF-G
binds to A site to promote translocation following peptide bond formation