Which molecule contains an amino acid binding site?

Which molecule contains an amino acid binding site?

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

Answer: (A)

In translation, amino acids are delivered to the ribosome by transfer RNA, and the key feature is that tRNA has a site at its 3' end where the amino acid is covalently attached to the terminal adenosine of the CCA sequence. This aminoacyl-tRNA is formed by aminoacyl-tRNA synthetases, which activate the amino acid with ATP and then transfer it to the tRNA, creating an ester bond. The charged tRNA then brings the correct amino acid to coincide with its codon on the mRNA, ensuring accurate incorporation into the growing protein. The other molecules—mRNA, rRNA, and DNA—do not carry amino acids in this way: mRNA provides the code, rRNA forms the ribosome, and DNA stores genetic information. Hence, the molecule that contains an amino acid binding site is tRNA.

In translation, amino acids are delivered to the ribosome by transfer RNA, and the key feature is that tRNA has a site at its 3' end where the amino acid is covalently attached to the terminal adenosine of the CCA sequence. This aminoacyl-tRNA is formed by aminoacyl-tRNA synthetases, which activate the amino acid with ATP and then transfer it to the tRNA, creating an ester bond. The charged tRNA then brings the correct amino acid to coincide with its codon on the mRNA, ensuring accurate incorporation into the growing protein. The other molecules—mRNA, rRNA, and DNA—do not carry amino acids in this way: mRNA provides the code, rRNA forms the ribosome, and DNA stores genetic information. Hence, the molecule that contains an amino acid binding site is tRNA.