This polypeptide is not necessarily an active protein. Allproteins in prokaryotic cells start with Met when synthesized,but not all proteins have Met first in their active form. It isoften necessary to clip off this Met after the polypeptide hasbeen synthesized to give a protein with a different N-terminalamino acid.
The signal to start making a polypeptide chain in simple,prokaryotic cells is the triplet AUG, which codes for the aminoacid methionine (Met). The synthesis of every protein in thesecells therefore starts with a Met residue at the N-terminalend of the polypeptide chain. After the tRNA that carries Metbinds to the start signal on the messenger RNA, a tRNA carryingthe second amino acid binds to the next codon. A dipeptide issynthesized when the Met residue is transferred from the firsttRNA to the amino acid on the second tRNA. If the DNA describedin this section were translated, the dipeptide would be Met-Phe(reading from the N-terminal to the C-terminalamino acid).
Biology- DNA, RNA, Protein Synthesis Flashcards | Quizlet
Assume that the DNA chain that codes for the synthesis of a particular protein contains the triplet A-G-T (reading from the 3´ to the 5´ end). Predict the sequence of nucleotides in the triplet, or codon, that would be built in the messenger RNA constructed on this DNA template. Then predict the amino acid that would be incorporated at this point in the protein.