Describe the process of transcription

Transcription is the process of transcribing the DNA code into another type of code or message - mRNA (messenger RNA). 

An enzyme called RNA polymerase binds to a specific part of a DNA sequence called the promoter (this acts as a signal to the cell to begin transcription). The DNA then must unzip and unwind to expose the two strands of DNA.

One strand, containing bases complementary to that of the gene needing to be transcribed, acts as a template - through complementary base pairing, nucleotides align alongside the template strand (A with U, G with C), forming a single-stranded mRNA molecule.

When the RNA polymerase recognises that it has reached a terminator sequence or stop codon (the end of the sequence encoding that specific gene), the mRNA detaches from the DNA. The DNA re-winds behind the RNA polymerase as it translocates (moves along) across the DNA strand.

The mRNA molecule then moves out of the nucleus, through a nuclear pore, into the cytoplasm - ready to be translated into a protein at the site of a ribosome.