Question

The nucleotide sequence of a DNA codon is CTA. A messenger RNA molecule with a complementary codon is transcribed from the DNA. In the process of protein synthesis, a transfer RNA pairs with the mRNA codon. What is the nucleotide sequence of the tRNA anticodon?

Select one:

a. GAU

b. GAT

c. CTA

d. CTA

e. CUA

Answer 1

e. CUA is the correct answer.

Protein synthesis involves two major steps

1.Transcription 2.Translation

• During the first step m RNA is created from DNA template. Here the nucleotide sequence of DNA is CTA. So nucleotide sequence of m RNAis GAU​​(Complementary bases are adenine and thymine, guanine and cytosine. But in RNA instead of Thiamine , Uracil is present )
• The m RNA combines with t RNA and r RNA complex to translate m RNA sequence in to an amino acid sequence or protein.
• Each t RNA has a set of 3 bases known as anticodon which is complementary to mRNA sequence.
• Here the mRNA sequence is GAU so the nucleotide sequence of t RNA anticodon must be CUA..