Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
43 Cards in this Set
- Front
- Back
|
tRNA Structure
|
Cloverleaf, 3D tertiary is L shaped
|
|
|
3' end of tRNA
|
Amino Acid binding site c-c-a sequence
|
|
|
TΨC
|
Where tRNA binds to ribosome
|
|
|
D loop
|
recognized by tRNA synthetase enzyme
|
|
|
Anticodon loop
|
Anticodon loop which is complementary to the codon of messenger RNA
|
|
|
Isoacceptor
|
Recognizes different codons but codes for same amino acid.
|
|
|
Activation
|
When AA is coupled to corresonding spot on tRNA catalyzed by Amino Acyl tRNA Synthetase
|
|
|
Initiation factors
|
Special proteins that dissociate the Ribosomes
|
|
|
Eukaryotic Ribosomal subunit
|
40, 60 = 80
|
|
|
Prokaryotic Ribosomal subunit
|
50, 30 = 70
|
|
|
tRNA f met
|
Initiation code for prokaryotes
|
|
|
prokaryote initiation factors
|
If 1,2,3
|
|
|
Prokaryotic Initiation
|
1. IF 1 and 3 bind to free 30s
2. mRNA then also binds to 30s 3. If2 (GTP) binds tRNA f-met, which binds AUG @ p site 4. If2/GTP is hydrolyzed, IF1 and 3 are lost, and 70s ribosome is formed 5. Reassembled Ribosome contains A P and E sites |
|
|
EIF-43
|
Eukaryotic Initiation factor 4e - cap binding factor essential for lining up start codon
|
|
|
A P E sites
|
Acceptor site, Exit site, Peptide site
|
|
|
AUG
|
can be placed directly into p site
is followed by tRNA f met or tRNA met |
|
|
Shine Delgarno sequence
|
10 nucleotides from AUG
Allows binding and proper orientation of mRNA with ribosome |
|
|
Monocistronic
|
1 AUG, 1 protein per mRNA.
|
|
|
Kozac sequence
|
Messages which are close to kozac sequence will translate efficiently.
|
|
|
3 stages of elongation
|
Binding, peptide bond formation, Translocation
|
|
|
catalyzes peptide bond formation
|
Ribosomal RNA
|
|
|
Peptide bond formation
|
α-amino group from AA in A site attacks Ester bond of AA in P site
|
|
|
Binding
|
Amino acyl trna forms complex with ef-tu/ef-g and then binds ribosome, GTP is hydrolyzed and EFTU is released
|
|
|
Polyribosome
|
A bunch of ribosomes synthesize off of the same mrna at once.
|
|
|
Distance btw ribosomes of polyribosome
|
100 nucleotides
|
|
|
Translocation
|
EFG and GTP hydrolysis, ribosome moves down one step
|
|
|
E. Coli energy requirements
|
30-50 percent of total ATP and GTP
|
|
|
Energy of Activation
|
formation of trna-aa complex requires 2 atp
|
|
|
Elongation energy
|
1 GTP per amino acid
|
|
|
Initiation AA in eukaryotes
|
Methionine
|
|
|
How to inhibit translation in eukaryotes
|
Phosphorylation of eIF-2
|
|
|
5' cap
|
proper positioning of mRNA on 40s subunit
|
|
|
Signal peptide
|
The signal for a protein to bind to the membrane, found in the first 15-30 amino acid. Rich in hydrophobic residues which allows ER to recognize it.
|
|
|
SRP
|
signal recognition particle
binds to signal peptide to prevent translation of ribosome until it docks with membrane |
|
|
Ribophorin
|
binds ribosome on ER
|
|
|
Membrane proteins
|
contain a hydrophobic stop transfer sequence that cause them to stay in the membrane
|
|
|
cycloheximide
|
inhibits peptide bond formation in eukaryotic cells
|
|
|
Diptheria Toxin
|
Inhibits Translocation (catalyzes rxn between nad+ and eukaryotic Elongation Factor
|
|
|
Chloramphenicol
|
Inhibits peptide bond formation, can inhibit mitochondrial protein synthesis at high levels. In both eukaryotes and prokaryotes
|
|
|
Puromycin
|
Terminates translocation by accepting amino acid from P sight instead of letting it go to the A site in both eukaryotes and prokaryotes
|
|
|
Tetracycline
|
Inhibits binding of amino-acyl tRNAs to A site on Ribosome in prokaryotes
|
|
|
Streptomycin
|
Binds to 30 s subunit and causes it to dissociate which inhibits translation in prokaryotes
|
|
|
Erythromycin
|
binds to 50s subunit and inhibits translocation in eukaryotes.
|
