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DNA transcription can also be known as RNA synthesis as it is when the DNA is copied as RNA. This carries the information needed for protein synthesis. Its three stages are:

1. Initiation

During initiation, transcription factors recognize the promoter and assemble at start of a gene. The RNA polymer II binds to the 3' end of the template strand to begin a new strand at the promoter sequence. The transcription initiation complex is a group of proteins necessary for transcription, including RNA polymer II and the transcription factors. 

2. Elongation

Elongation occurs when the double helix unwinds and the RNA polymer reads the template strand of DNA. RNA polymer II adds on new nucleotides to the 3' end of the newly synthesized RNA strand at the same time while tRNA is being accepted. Because the new strand is RNA, its code will be similar to the coding strand due to antiparallel strands, with the exception of "T" being replaced with "U". The RNA strand elongates 5' to 3'.

3. Termination

When RNA polymer II completes its run, the RNA synthesis process is over. For this to happen RNA polymer II must reach the end code of the gene, or the terminator, AAAUAAA. Both RNA and DNA are then released. To stablize the premRNA, a "G-cap" is introduced to the 5' due to G being double bonded, and a "poly-A-tail", to the 3' end. Next a spliceosome preforms RNA splicing, by cutting out noncoding segments, or introns and leaving coding introns, exons, remaining. Then the spliceosome joins together the remaining exons to create the final mRNA sequence. 

Spliceosomes are composed of snRNPs (small nuclear ribonucleoproteins) and for each of those, a snRNA (small nuclear RNA molecue).

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