Transcription of DNA occurs in the nucleus, according to Cara Lea Council-Garcia, a professor at the University of New Mexico. The DNA is transcribed into messenger RNA in the nucleus of a cell.
DNA acts as the instructions to build proteins. The instructions are not in a language that will be understood by the parts that will later assemble the proteins. This is why it is necessary for transcription to occur first. The DNA is unzipped so that the RNA polymerase enzyme will run along the strand that is used as a template for building. The strand that will be used may be recognized by the presence of T A C nucleotides. The RNA polymerase will add complementary RNA as it matches up to the nucleotides. "G" will match up with "C," the DNA "A" with "U," and "T" with the RNA "A."