Describe the process and purpose of transcription

The purpose of transcription is to produce an mRNA copy of a gene, to allow the genetic information to pass out of the nucleus, through the nuclear pores where it can be used to assemble a protein.

•  Enzyme DNA helicase uncoils a region of the DNA double-helix by breaking the hydrogen    bonds between the base pairs.

• Complementary nucleotides from the nucleoplasm align up to the exposed base pairs on the template DNA strands

• The enzyme RNA polymerase moves along the strand, joining adjacent nucleotides together by phosphodiester bonds.

• This process continues until RNA polymerase reaches a stop codon and the production of pre-mRNA is complete.

• Non-coding introns are then spliced out by enzymes in the spliceosome and the mRNA strand leaves the nucleus.