rubensssss
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As part of the DR Aviso Protein Elongation team, you have been trying for the last 2 years to isolate the peptydil transferasa activity from the robosoms. Your work,so far,has been in vain. Your effort may lead nowhere because
A-The activity may not really exist, the peptide chain elongates expontaneouly
B-Tha transferasa activity occurs only in the presence of elongation factors.
C-the peptidyl transferasaactivity is intimately associated with ribosomal proteins and Rrna.
D-The transferas activity canot be separated from charged tRNAs.
E-The transferasa activity can not be separated from mRNA.
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| mash
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is it bcoz peptidyl transferase is a part of large subunit of ribosome?
if dat is so then ans is C..
wats d ans?
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| rida
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hmmm maybe D, since they work in accordance with tRNA's, but not sure
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| rubensssss
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A very puzzling aspect of the series of elongation steps in protein trnslation has been the enzyme activity of peptidil transferase.Attemps at dissecting out this activity from the ribosome have met with uniform failure. It seems that the enzymatic activity can not occur without the contex of the ribosome. In the case of E.coli. the activity has been shown to rely on the prsence of several ribosomal protein and rRNA. it may well be the case that this activity is reminiscent of an ancestral ribosomal activity that may have been used in formation of primeval proteins.
another aspect of the elongation system occurs as a motif in the biochemistry of cellular system. Elongation Factor eEF1 as is component of a GTP cycle, and in both cases of eEF1 a andeEF2,GTP acts as a modulator of comformation changes in the 2 factors.When each of the 2 factors is GTP bound,its respective affinity for its ribosomal targets is higher than when the factor isGDPbound. In the case of eEF1 a, the factor becomes GTP bound as part of the cycle.When the factor exits from the ribosome in in the GDP form,it combines with another factor labelled,eEF1 b,which binds it by displacing the GDP from its site.When eEF1 a is required fo the next cycle.GTP then displaces the eEF1 b factor from the eEF1 a-eEF1 b complex.The newly charged eEF1 a complex then goes on to form a new ternary complex with an aminoacid charged tRNA.In this fashion this elongation factor cycles within a cycle during protein elongation.This Type of GTP cycle occurs as well in prokariotic protein elongation and in a modified fashion in cycling of membrane receptors.
Answer C.
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