Study BMB 400 Chap 14 Ribosome Flash Cards

 
Pile Management Card
BMB 400 Chap 14 Ribosome

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polypeptide exiting channel
-only alpha helices can fit
-no B sheets
-other 2ary or 3ary have to form later
mRNA binding channel
-only ssRNA can fit
-removes 2ary structures
kinky...
...there's a kink in the mRNA site between A and P sites to facilitate maintenance of the correct reading frame
E site
binding site for the tRNA that is released after the growing polypeptide chain has been transferred to the aminoacyl-tRNA (E is for exit)
P site
binding site for peptidyl-tRNA
A site
binding site for aminoacylated-tRNA
16S rRNA
-contacts anticodon loops
-decodes
-not some fancy-schmancy protein
peptidyl transferase center
-is composed entirely of RNA
The bond b/w the ____ tRNA bond and growing peptide bond is broken
peptidyl tRNA (P site)
New Amino Acids Are Attached to the _______ of the Growing Polypeptide Chain
-C terminus
There is 1 ribosome for every ___ nucleotides of mRNA
80
Polyribosome
-mRNA bearing >1 ribosome

-if not, 90% of ribosomes just sittin' around doin' nuthin'
Small subunit of ribosome consists of...
...Decoding center: charged tRNAs read mRNA codons ("A")
-mRNA binding site
Large subunit of ribosome consists of...
...Peptidyl transfer center: forms peptide bonds ("P")
...Peptide exit channel ("E")
What's % for ribosome?
Ribosome consists of 2 subunits
60% RNA
40% protein
What's the translation speed?
-Translation speed of ribosome = 20 aa/sec (60 nt/sec)
RNA polymerase synthesizes 50-100 nt/sec
in euks, do RNA polymerase and translation happen on same mRNA?
-NO!!
-only in pros
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