What is the role of tRNA in translation?

• A. It helps to assemble ribosomal subunits.
• B. It carries amino acids to the ribosome and matches codons to anticodons.
• C. It helps to unwind the DNA double helix.
• D. It transcribes RNA from DNA.

Answer: (B)

tRNA acts as the adaptor that translates the genetic code into a protein by delivering the correct amino acids to the ribosome and reading the mRNA codons through its anticodon. Each tRNA is charged with a specific amino acid by an aminoacyl-tRNA synthetase, so when a tRNA with a matching anticodon encounters a codon on the mRNA, it pairs specifically and the ribosome can add that amino acid to the growing chain. This pairing—codon on mRNA with anticodon on tRNA—ensures the amino acids are assembled in the correct order. The ribosome catalyzes the peptide bond formation, then the tRNA shifts through the ribosome during translation.

Wobble base pairing at the third position of a codon allows some tRNAs to recognize more than one codon for the same amino acid, providing flexibility without changing the amino acid sequence.

Other options describe processes not carried out by tRNA in translation: assembling ribosomal subunits is done by rRNA and ribosomal proteins; unwinding the DNA double helix is the job of helicases; transcription of RNA from DNA is performed by RNA polymerase.