Transcription of DNA to RNA

There are significant differences in the process of transcription in prokaryotes versus eukaryotes.

• In prokaryotes (bacteria), transcription occurs in the cytoplasm. Translation of the mRNA into proteins also occurs in the cytoplasm. In eukaryotes, transcription occurs in the cell's nucleus. mRNA then moves to the cytoplasm for translation.

• DNA in prokaryotes is much more accessible to RNA polymerase than DNA in eukaryotes. Eukaryotic DNA is wrapped around proteins called histones to form structures called nucleosomes. Eukaryotic DNA is packed to form chromatin. While RNA polymerase interacts directly with prokaryotic DNA, other proteins mediate the interation between RNA polymerase and DNA in eukaryotes.

• mRNA produced as a result of transcription is not modified in prokaryotic cells. Eukaryotic cells modify mRNA by RNA splicing, 5' end capping, and addition of a polyA tail.