Changes

'''RNA polymerases''', often abbreviated to '''RNAP''', are the enzymes in a cell responsible for [[transcription|synthesizing]] strands of [[RNA]].  Because this function is essential to life, all organisms (and quite a few viruses) contain at least one type of RNA polymerase (most organisms contain at least three types).  Depending on the RNA polymerase, transcription requires either a [[DNA]] or an RNA template; although, in most contexts, "RNA polymerase" refers to the DNA-dependant RNA polymerases that use a DNA template to [[transcribe|transcription]] genes into [[mRNA]] ("messenger" RNA).  [[reverse transcriptase|Reverse transcriptases]] are enzymes (usually associated with [[retrovirus|retroviruses]])that perform the opposite function, using an RNA template to synthesize a [[DNA]] product.

'''RNA polymerases''', often abbreviated to '''RNAP''', are the enzymes in a cell responsible for [[transcription|synthesizing]] strands of [[RNA]].  Because this function is essential to life, all organisms (and quite a few viruses) contain at least one type of RNA polymerase.  Depending on the RNA polymerase, transcription requires either a [[DNA]] or an RNA template; although in most contexts, "RNA polymerase" refers to the DNA-dependant RNA polymerases, which use a DNA template to [[transcribe|transcription]] genes into [[mRNA]] ("messenger" RNA).  [[reverse transcriptase|Reverse transcriptases]] are enzymes (usually associated with [[retrovirus|retroviruses]]) that perform the opposite function, using an RNA template to synthesize a [[DNA]] product.

 

 

Most [[prokaryote|prokaryotes]] and [[archaea|archaeans]] use the same RNA polymerase to transcribe [[mRNA]] and functional non-coding RNAs (e.g. [[rRNA|ribosomal RNAs]] or [[tRNA|transfer RNAs]].  However, [[eukaryote|eukaryotes]] (organisms in which the genetic material is contained within a [[nucleus]]) use specialized RNAPs, each responsible for transcribing different classes of RNA.