The two important steps in protein synthesis are “transcription and translation.” During protein synthesis, mRNA (messenger RNA) is synthesised under the direction of DNA (deoxyribonucleic acid).
The transcription results in the production of an mRNA, which then enters into the cytoplasm. The message carried by mRNA is translated into amino acid polypeptides in the cytoplasm.
Thus, the blanks can be filled with DNA, RNA; protein.