Amino acids are attached to their $tRNA$ molecules by which of the following enzymes?

• A. Ribosomal $RNA$ polymerase
• B. Aminoacyl-$tRNA$ synthetase
• C. Peptidyl transferase
• D. $DNA$ ligase

Answer: (B)

Verified step by step guidance

1. Begin by understanding the role of tRNA in protein synthesis. tRNA molecules are responsible for bringing amino acids to the ribosome during translation.
2. Recognize that each tRNA molecule must be charged with the correct amino acid before it can participate in protein synthesis. This charging process is crucial for accurate translation.
3. Identify the enzyme responsible for attaching amino acids to their corresponding tRNA molecules. This enzyme is known as aminoacyl-tRNA synthetase.
4. Aminoacyl-tRNA synthetase catalyzes the esterification of an amino acid to its corresponding tRNA, forming an aminoacyl-tRNA complex. This process requires ATP and is highly specific, ensuring that each tRNA is charged with the correct amino acid.
5. Understand that other enzymes listed, such as ribosomal RNA polymerase, peptidyl transferase, and DNA ligase, have different functions. Ribosomal RNA polymerase is involved in RNA synthesis, peptidyl transferase forms peptide bonds during translation, and DNA ligase joins DNA strands.