How is lac operon regulated quizlet?

The lac operon is regulated by specific protein which turn it on when it is an environment where the food source is lactose, it would begin to turn the lactose into digestible galactose and glucose. When it is not around lactose on the other hand, it is switched off by proteins that bind to DNA and block transcription.

How is the operon regulated?

Each operon contains regulatory DNA sequences, which act as binding sites for regulatory proteins that promote or inhibit transcription. Regulatory proteins often bind to small molecules, which can make the protein active or inactive by changing its ability to bind DNA.

How is the lac operon activated?

The lac operon is an inducible operon that utilizes lactose as an energy source and is activated when glucose is low and lactose is present.

How does regulation of transcription control the lac operon?

The lac operon is therefore positively regulated by the absence of glucose catabolites (Figure 1). Enhanced RNA polymerase binding leads to a high rate of transcription and translation of the lac operon structural genes lacZ, lacY, and lacA. The protein products of lacZ, lacY, and lacA metabolize lactose into glucose.

Which regulatory mechanisms does the lac operon operate under?

Bacterial lac operon. The lac operon functions by a repression mechanism. (A) An inhibitor protein, lacI, binds to regulatory sites lacO in the promoter (P) and turns off transcription of the genes required for lactose metabolism.

How are lac genes turned off and on quizlet?

The lac genes are turned off by repressors and turned on by the presence of lactose. Describe how most eukaryotic genes are controlled.

How are prokaryotic genes regulated?

Prokaryotic cells can only regulate gene expression by controlling the amount of transcription. It therefore became possible to control gene expression by regulating transcription in the nucleus, and also by controlling the RNA levels and protein translation present outside the nucleus.

What is the regulation of a lac operon by a repressor known as?

The protein that is formed by the lacI gene is known as the lac repressor. The type of regulation that the lac operon undergoes is referred to as negative inducible, meaning that the gene is turned off by the regulatory factor (lac repressor) unless some molecule (lactose) is added.