Which molecule carries amino acids to the ribosome during translation?

• A. Brings amino acids to the ribosome
• B. Forms the core of the ribosome
• C. Serves as a template for mRNA
• D. Catalyzes peptide bond formation

Answer: (A)

During translation, the adaptor molecule transfer RNA delivers amino acids to the ribosome in the order dictated by the mRNA. Each tRNA carries a specific amino acid and has an anticodon that pairs with the corresponding codon on the mRNA, ensuring the right amino acid is added at the right place. Before use, amino acids are attached to their tRNAs by aminoacyl-tRNA synthetases, forming charged tRNAs. When a charged tRNA binds the ribosome, the amino acid it carries is transferred to the growing polypeptide chain, a peptide bond formed by the ribosome’s RNA-based catalytic activity. The other descriptions refer to different roles: the ribosome’s core is built from rRNA, the template for mRNA is DNA (or the mRNA itself), and peptide bonds are catalyzed by the ribosome, not by tRNA.