Which molecule carries amino acids to the ribosome during protein synthesis?

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

Answer: (A)

During protein synthesis, amino acids are delivered to the ribosome by transfer RNA (tRNA). Each tRNA carries a specific amino acid and contains an anticodon that pairs with the corresponding codon on the messenger RNA (mRNA), ensuring the correct amino acid is added to the growing polypeptide. The aminoacyl-tRNA synthetases charge tRNAs with their specific amino acids, and the ribosome uses the tRNA in the A site to form peptide bonds with the growing chain in the P site, with the tRNA that has relinquished its amino acid exiting through the E site. In contrast, mRNA provides the code that specifies which amino acids to add, rRNA forms the ribosome and catalyzes peptide bond formation, and DNA stores the genetic information. Thus, the molecule that carries amino acids to the ribosome is tRNA.