Chapter 16 - Regulation of Gene Expression - 16.1 - Prokaryotic Gene Expression Is Regulated in Operons - 16.1 Recap - Learning Outcomes - Page 341: 3

In inducible systems, the attachment of the effector to the repressor will significantly reduce the affinity of the repressor for the operator. In this case, the repressor is released and transcription is allowed to continue (Ex: lac operon). In repressible systems, the binding of the effector to the repressor will boost the affinity of the repressor for the operator, thus halting transcription (Ex: try operon).

In inducible systems, the attachment of the effector to the repressor will significantly reduce the affinity of the repressor for the operator. In this case, the repressor is released and transcription is allowed to continue (Ex: lac operon). In repressible systems, the binding of the effector to the repressor will boost the affinity of the repressor for the operator, thus halting transcription (Ex: try operon).