Which RNA molecule brings amino acids to the ribosome during translation?

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

Answer: (D)

During translation, the ribosome reads the mRNA sequence and builds a protein by adding the corresponding amino acids. The molecule that brings each amino acid to the ribosome is transfer RNA. Each tRNA carries a specific amino acid and has an anticodon that pairs with a complementary codon on the mRNA, ensuring the correct amino acid is added for each codon. The amino acid is attached to the tRNA by an enzyme called an aminoacyl-tRNA synthetase, forming an aminoacyl-tRNA. As the ribosome moves along the mRNA, tRNAs enter the A site, their amino acids are linked to the growing polypeptide in the P site, and the deacylated tRNA exits from the E site. Other RNA types have different roles—mRNA provides the template sequence, rRNA forms the ribosome and catalyzes peptide bond formation, and snRNA is involved in RNA processing. So, the RNA molecule that brings amino acids to the ribosome is tRNA.