operons 101 - Operons 101 What is an operon? An operon is a...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Operons 101 What is an operon? An operon is a transcription unit in which genes that serve a related function are grouped and controlled by a single “switch,” or a segment of DNA known as the operator . If several genes code for proteins that serve similar or complementary functions, it makes sense to group these genes into an operon because often the proteins encoded by these genes will be used under similar circumstances. For example, if several genes encode proteins that are all involved in different aspects of metabolism of a certain substrate, it makes sense that in the presence of that substrate, the transcription of all of these genes can be turned on at once without needing multiple different signals. An operon is fundamentally a segment of DNA containing clustered genes, and thus it can be transcribed into mRNA which can be translated into protein. In this class, we mostly talked about operons as a form of regulating gene expression in prokaryotes such as E. coli , but operons can also be found in some eukaryotes. Operons contain a promoter region and an operator . The operator may be contained in the promoter or located between the promoter and the genes of the operon. The promoter is where RNA polymerase binds to transcribe the genes of the operon. Another component to know is the repressor , which is a protein that can bind to the operator in order to prevent RNA polymerase from binding to the promoter and transcribing the operon. The Lac Operon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/20/2011 for the course CHEMISTRY 120 taught by Professor Head-gordon during the Spring '11 term at ASU.

Page1 / 2

operons 101 - Operons 101 What is an operon? An operon is a...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online