Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Protein Synthesis P2

Protein Synthesis Part 2

QuestionAnswer
IF-3 referred to as an anti-associtation factor. Binds to 30s
IF-2, GTP & initiator tRNA 30s initiation complex. Binding of mRNA
In Pro what recognizes the shine delgarno sequence? The 3' end of 16s rRNA recognizes the purine rich sequence. Then when 50s binds you get 70s complex
What does f-Met-tRNA have to bind to in the ribosome? The P site of the ribosome
Name the steps of the elongation phase Binding of amino-acyl tRNA, peptide bond formation, translocation, repeat of this process
What does the binding of the 2nd aminoacyl tRNA sequence need for elongation? Presentation of an elongation ternary complex. GTP required. Requires EF-TU (Pro) or EF-1alp (Euk). Binds to A site starting elongation process
What happens after 2nd aminoacyl binds? Peptide bond formation b/w 2nd and 1st aminoacyl tRNA located at P site. Outcome is dipeptide tRNA located at A site. P site is now free (deacylate tRNA) of AA
Describe translocation Requires EF-G & GTP. 1st aminoacyl tRNA gets ejected from P site to E site. Elongated peptide bond translocates from A site to P site. Ribosome is being moved in 5' to 3' direction cocurrently.
How is the hydrolysis of GTP and EF used for delivering aminoacyl tRNA to A site presented? Presented in the form as EF-TU together with the nucleotide GDP. GDP & GTP exchange is catalyzed by EF-TS
What catalyzes peptide bond formation? Ribozyme peptidyl transferase
What does the termination step require? GTP. Release causes the hydrolysis of peptidyl-tRNA so it can be released
Describe Euk intiation complex formation eIF-2 forms an initiation ternary complex which binds to 40s with eIF-3 to form a complex that binds with mRNA. Then 60s complex binds to form 80s initiation complex
What 2 Euk initiation factors can limit the formation of the 80s initiation complex? eIF-2 and eIF-4. eIF-2-GDP has to be regenerated to eIF-2-GTP by eIF-2B
Describe Euk mRNA m7G is recognized by eIF-4E. 5'UTR recognizes the first initiation. Many viral mRNA and 10% of mRNA have IRES and no cap
beta and alpha globin beta globin is a much better recruiter of mRNA relative to alpha globin. beta globin has a secondary structure that is more favorable to being unwound
IRES mRNA's long 5' UTR 400-500nts. Can have secondary structures very high in G & C content.Usually encode for proteins with specialized functions
What does virally encoded protease do? Degrades eIF-4G. host mRNA is no longer translated in a very efficient way b/c it has a truncated eIF-4G that lacks the ability to recognize eIF-4E
Translational Control Ability to modulate the tranlability of the mRNA in the absence of any transcriptional input. There is no change in mRNA content/no trascriptional input.
Describe the alternate pathway for eIF-2-GDP (Translational Control) Kinase mediated phosphorylation at alpha subunit at serine, eIF-2 continues to bind with eIF-2B and sythesis is at standstill
Describe alternative pathway for eIF-4 (translational control) Binds to eIF-4E binding protein. Brings eIF -4E into a form that is incapable in being engaged in mRNA binding
How does insulin play a role in eIF-4E? Brings about a set of kinases that can phosphorylate eIF-4E 7 its binding protein so it can no longer associate with eIF-4D as normal to bind mRNA
Signal peptide Sequence of AA residues that is highly enriched in hydrophobic amino acid residues.
How is signal peptide sythesized? Ribosome is cytosol & protein is tagged. SRP binds and stalls synthesis. SRP has to dock a docking protein or SRP receptor. GTP hydrolyzed and SRP released.
Name inhibition drugs Cyclohexamide of Euk inhibits peptidyl transferase. Puromycin of Euk and Pro resembles charged tRNA , binds to A site and terminates process
Ricin Ribosome inactivating protein. Catalyzes depurination of rRNA at 28S rRNA. Formation of an Abasic site at the RNA level, not DNA level