Question

An mRNA has the stop codon 5'UAA3'. What tRNA anticodon will bind to it?

1. 5" ACU3'
2. 5'AUC3"
3. 5'ATT3'
4. none

Answer 1

The tRNA anticodon that will bind to the mRNA stop codon 5'UAA3' is 5'AUU3'. So the correct option is 2. 5'AUC3

Step-by-step explanation:

In the genetic code, the mRNA codon 5'UAA3' is a stop codon, which signals the termination of protein synthesis. To find the corresponding tRNA anticodon, we need to refer to the codon-anticodon pairing rules. In RNA, adenine (A) pairs with uracil (U). Therefore, the anticodon for the mRNA stop codon 5'UAA3' would be 5'AUU3'. Each nucleotide in the mRNA codon forms a complementary base pair with the corresponding nucleotide in the tRNA anticodon.

Now, let's break down the explanation further. The first nucleotide in the mRNA codon is 'U', and its complement is 'A', so the first nucleotide in the anticodon is 'A'. The second nucleotide in the mRNA codon is 'A', and its complement is 'U', so the second nucleotide in the anticodon is 'U'. Finally, the third nucleotide in the mRNA codon is 'A', and its complement is 'U', so the third nucleotide in the anticodon is also 'U'. Therefore, the tRNA anticodon that will bind to the mRNA stop codon 5'UAA3' is 5'AUU3'.

In summary, the tRNA anticodon 5'AUU3' is the correct answer because it follows the base pairing rules in RNA, providing a complementary sequence to the mRNA stop codon 5'UAA3', thereby facilitating the termination of protein synthesis.So the correct option is 2. 5'AUC3