This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Chian initiation in protein synthesis is by 
Select and explain. 
A. AUG, B. GLA, C. UGA, D. UAG
A: AUG
Answer: A: AUG 
Explanation: INITIATOR CODON : AUG is the initiator codon. It also acts as the codon for methionine. In a few proteins, GUG acts as initiator codon. REF :DM VASUDEVAN TEXTBOOK ; 8th EDITION ;Page no :586.