This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Fidelity of protein translation depends on 
Select and explain. 
A. RNA polymeraes, B. DNA polymeraes, C. M-RNA polymeraes, D. Amino acyl t-RNA synthetase
D: Amino acyl t-RNA synthetase
Answer: D: Amino acyl t-RNA synthetase 
Explanation: In translation, proof reading of mRNA is done by Amino acyl- tRNA synthetase. Amino acyl t-RNA synthetase is responsible for fidelity (faithfulness) of protein translation.