Which enzyme is responsible for charging tRNA with amino acids?

Which enzyme is responsible for charging tRNA with amino acids?

• A. Aminoacyl-tRNA Synthetase
• B. DNA Polymerase
• C. RNA Polymerase
• D. Helicase

Answer: (A)

Charging tRNA with amino acids is the step that links the genetic code to protein synthesis. The enzyme responsible is aminoacyl-tRNA synthetase, and each amino acid has its own specific synthetase that recognizes both the amino acid and its corresponding tRNA. The enzyme activates the amino acid using ATP to form aminoacyl-AMP, then transfers the amino acid to the 3' end of the tRNA, yielding aminoacyl-tRNA. This charged tRNA can then enter the ribosome and add the correct amino acid to the growing polypeptide according to the mRNA codon. The other enzymes listed perform different roles: DNA polymerase copies DNA, RNA polymerase transcribes RNA, and helicase unwinds DNA.

Charging tRNA with amino acids is the step that links the genetic code to protein synthesis. The enzyme responsible is aminoacyl-tRNA synthetase, and each amino acid has its own specific synthetase that recognizes both the amino acid and its corresponding tRNA. The enzyme activates the amino acid using ATP to form aminoacyl-AMP, then transfers the amino acid to the 3' end of the tRNA, yielding aminoacyl-tRNA. This charged tRNA can then enter the ribosome and add the correct amino acid to the growing polypeptide according to the mRNA codon. The other enzymes listed perform different roles: DNA polymerase copies DNA, RNA polymerase transcribes RNA, and helicase unwinds DNA.