Which molecule brings amino acids to the ribosome during translation?

• A. tRNA
• B. mRNA
• C. rRNA
• D. DNA

Answer: (A)

Transfer RNA is the adaptor that brings a specific amino acid to the ribosome and matches it to the corresponding codon in the mRNA through its anticodon. During translation, the ribosome reads mRNA codons and accepts charged tRNAs at the A site; the anticodon base-pairs with the codon, the amino acid is transferred to the growing polypeptide, and peptide bonds are formed by the ribosome’s RNA catalyst. The amino acid is attached to tRNA by aminoacyl-tRNA synthetases, providing the correct matching of amino acids to codons. Other molecules play different roles: mRNA provides the template sequence, rRNA forms and helps drive the ribosome’s catalytic activity, and DNA stores genetic information in the genome but does not deliver amino acids to the ribosome.