Operon model simply explained
You will encounter the operon model in biology during the final years of school. As a rule, this model is described in the Abitur. It is a model from genetic biology that is quite demanding and therefore difficult to understand for many students. However, it can also be explained quite simply.
The operon model has not been defined for very long. In 1960 it was developed by two French scientists. Since it was named after the two scientists, you will often read that it is the Jacob and Monod operon model. They treat the model in the context of the genetic biology.
The operon is a sector of DNA
- In order to explain the model, the first thing you should know is what an operon is. The operon is part of the DNA strand. This forms the starting point of the so-called RNA polymerase. This has to run smoothly if it is to be ensured that protein synthesis is precisely controlled. If this gets out of step, the formation of proteins is disturbed. Too many or too few proteins would be produced.
- The operon consists of three sections: The promoter is the actual starting point for the RNA polymerase. The operator is where repressors or activators can dock. The third section contains the structural genes. All information about which proteins are intended to be synthesized is stored in these.
The model describes the transcription of genes
- You cannot avoid learning the terminology when describing the operon model. The RNA polymerase can run smoothly without imbalance as long as no repressor attaches to the operon. In this case the genes are transcribed without interruption. A repressor is a protein that binds the operator to the DNA and in this way blocks the RNA polymerase.
- In their research, the French scientists found out how this gene transcription can be stopped, namely by docking a repressor on the operon. The structural genes, which are constantly read and synthesized without the repressor, can be changed by the repressor. This stops the RNA polymerase and thus the entire transcription of the genes. By consciously adding active repressors, the gene transcription can be controlled consciously.
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The operon model explains this relationship in a graphical representation. It can be seen from this that the RNA polymerase takes place in the case of an inactive repressor and is disrupted in the case of an active repressor. The graphic representation is clear and you can easily explain it if you know the terminology. You need to memorize these if you want to explain the process.
