a. the first methionine in eukaryotic translation contains a formyl group.
Explanation:
Protein synthesis begins when the initiator aminoacyl tRNA carrying the initiator amino acid joins the mRNA-small ribosomal subunit complex. Procaryotes and eucaryotes differ from each other in the identity of the first initiator amino acid. In both types of organisms, "AUG" serves as an initiation codon. However, procaryotes have formyl-methionine joined to the amino acid arm of the initiator tRNA while eucaryotic initiator tRNA carries methionine as the first amino acid to be added to the protein.
