RNA polymerase must be able to recognize the beginning of a gene so that it knows where to start synthesizing an mRNA. = promoter sequence = a particular DNA sequence that appears at the beginning of genes.
DNA unzips and RNA polymerase enzyme binds to one strand of DNA
RNA polymerase makes an elongating chain of RNA nucleotides, each complementary to the DNA nucleotide it is hydrogen bonded to
The completed mRNA molecule is released from RNA polymerase - DNA complex and can begin translation. In eukaryotic cells this means first moving from the nucleus into the cytoplasm. In prokaryotic cells (bacteria), ribosomes can bind and begin translation before polymerase has completed of the new mRNA strand.