During translation, which statement best describes the role of tRNA anticodons?

• A. They catalyze peptide bond formation
• B. They unwind the DNA template
• C. They transcribe rRNA
• D. They pair with mRNA codons to determine amino acids

Answer: (D)

tRNA anticodons act as the decoder in translation. Each anticodon on a tRNA pairs with a complementary codon on the mRNA, so the amino acid carried by that tRNA is added at the right spot in the growing polypeptide. This base-pairing relationship ensures that the sequence of codons in the mRNA is translated into the correct sequence of amino acids. The other processes described—peptide bonds are formed by the ribosome's enzymatic activity, DNA is unwound by helicase, and rRNA is transcribed by RNA polymerase—happen in different steps or by different machines, not by the anticodon itself.