Which site is the aminoacyl tRNA site?

Which site is the aminoacyl tRNA site?

• A. The aminoacyl tRNA site
• B. The Exit site
• C. The Peptidyl tRNA site
• D. The Catalytic site

Answer: (A)

Charged tRNA molecules enter the ribosome at the aminoacyl tRNA site, which is the entry point for decoding the mRNA. This site is where the anticodon pairs with the mRNA codon and the new amino acid is prepared for incorporation into the growing polypeptide. After binding, the amino acid on this tRNA will form a peptide bond with the peptide chain carried by the tRNA in the peptidyl tRNA site. Then translocation moves the tRNAs so the growing chain sits in the peptidyl tRNA site and the spent tRNA exits via the exit site. The catalytic site refers to the peptidyl transferase center that actual performs the bond formation, not where tRNA initially binds. So the aminoacyl tRNA site is the entry point for charged tRNA.

Charged tRNA molecules enter the ribosome at the aminoacyl tRNA site, which is the entry point for decoding the mRNA. This site is where the anticodon pairs with the mRNA codon and the new amino acid is prepared for incorporation into the growing polypeptide. After binding, the amino acid on this tRNA will form a peptide bond with the peptide chain carried by the tRNA in the peptidyl tRNA site. Then translocation moves the tRNAs so the growing chain sits in the peptidyl tRNA site and the spent tRNA exits via the exit site. The catalytic site refers to the peptidyl transferase center that actual performs the bond formation, not where tRNA initially binds. So the aminoacyl tRNA site is the entry point for charged tRNA.