InterviewSolution
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InterviewSolution
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Question : How is a polypeptide chain formed during protein synthesis ? |
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Answer» Solution :(1) A polypeptide CHAIN is formedat the time of translation duringthe processof protein synthesis. It isformed duringthe elongation processat the time of translation. This process starts after the initiation takes place. Duringinitiation, m-RNA molecule is boundto RIBOSOMAL subunits. (2) Each t-RNA complex BRINGS a specific amino acid. The anticodons and codons are complementary to each otheras theappropirateamino acids are placed in theirproper position. (3) When appropriate amino acids are brought to the site of ribosomal subunits, there is the formation of peptidelinkagesbetween the successive amino acid molecules. The etire activityis cataylzed by an enzyme, peptidly transferase. It aslo requiresenergywhich is suppliedby ATP and GTPmolecules. (4) For the elongation, elongation factors are needed. (5)The movementof m-RNAis onecodon ahead each time and THEREFORE ONE aminoacidis addedin the polypeptide chaincausingsystematic elongation. (6) The ribosomersmove alongthe m-RNAin step-wise manner fromstartto stop codon in 5-3. directionduringtranslocation. Thiscauses polypeptide chainto grow. |
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