Question

What is the function of a non-sense codon?

• A. To release polypeptide chain from tRNA.
• B. To form an unspecified amino acid.
• C. To terminate the message of a gene controlled protein synthesis.
• D. To convert a sense DNA into non sense DNA.

Answer 1

Answer: (C)

To terminate the message of a gene controlled protein synthesis.

• The function of non-sense codons is to terminate the message of a gene controlled protein synthesis. The three stop codons have been given names - UAG is amber, UGA is opal, and UAA is ochre.
• Stop codons are also called "termination" or "nonsense" codons. They signal the release of the nascent polypeptide from the ribosome because there is no cognate tRNA that has anticodons complementary to these stop signals, and so a release factor binds to the ribosome instead.
  Hence, the correct answer is C.