<P> Transcription occurs in the cell nucleus , where the DNA is held . The DNA structure of the cell is made up of two helixes made up of sugar and phosphate held together by hydrogen bonds between the bases of opposite strands . The sugar and the phosphate in each strand are joined together by stronger phosphodiester covalent bonds . The DNA is `` unzipped '' ( disruption of hydrogen bonds between different single strands ) by the enzyme helicase , leaving the single nucleotide chain open to be copied . RNA polymerase reads the DNA strand from the 3 - prime ( 3 ' ) end to the 5 - prime ( 5 ' ) end , while it synthesizes a single strand of messenger RNA in the 5 ' - to - 3 ' direction . The general RNA structure is very similar to the DNA structure , but in RNA the nucleotide uracil takes the place that thymine occupies in DNA . The single strand of mRNA leaves the nucleus through nuclear pores , and migrates into the cytoplasm . </P>
where is the protien made in the cell
cell nucleus