Assertion : UAA, UAG and UGA terminate protei | vedclass

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(A) The synthesis of a polypeptide chain terminates when a stop codon (nonsense codon) of $mRNA$ reaches the $A-$site of the ribosome.There are three

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If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

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(A) The synthesis of a polypeptide chain terminates when a stop codon (nonsense codon) of $mRNA$ reaches the $A-$site of the ribosome.There are three stop codons: $UAA, UAG$,and $UGA$.These codons do not code for any amino acid and are not recognized by any $tRNA$ molecule.Because no $tRNA$ can bind to these codons,no further aminoacyl-$tRNA$ reaches the $A-$site.Consequently,the polypeptide chain is released from the $P-$site $tRNA$ in the presence of release factors,terminating the translation process.

Assertion : $UAA, UAG$ and $UGA$ terminate protein synthesis.
Reason : They are not recognised by $tRNA$.

Similar Questions

Which of the following codons acts as a stop signal?

How many genetic codes specify the amino acid proline?

Give scientific reasons: Unambiguous,universal,and degenerate are some of the terms used for the genetic code.

Select the correct statement with respect to the Wobble hypothesis.

$A$: Polypeptide sequences are dictated by $DNA$ and represented by $mRNA$.
$R$: Sequence of amino acids in a polypeptide can be predicted by the exact sequence of nucleotides on the $mRNA$ and template $DNA$.

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Assertion : $UAA, UAG$ and $UGA$ terminate protein synthesis.Reason : They are not recognised by $tRNA$.