Operon System

An operon system controls the rate of protein synthesis. There are two types of operons. The first type is called repressible operon, in which protein is being synthesized. In order to stop the process, an amino acid called tryptophan has to be created in order to transform the inactive repressor to active repressor. In this process, RNA polymerase reads DNA to create mRNA. So polypeptides are created for tryptophan. Then tryptophan can attach to protein that blocks the RNA polymerase.

Another type of operon is inducible operon. This type of system is not producing protein at first. Allolactose is served as an inducer to inactivate the repressor. In the Arabinose operon system, which is an inducible one, Arabinose is added to start the protein synthesis. RNA polymerase is able to come in and arabinase is produced to digest sugar. When there is too much enzyme, the system will shut off and the process would repeat over and over.