What would occur if the repressor of an inducible operon were mutated so it could not bind the operator? a. irreversible binding of the repressor to the promoter b. reduced transcription of the operon's genes c. buildup of a substrate for the pathway controlled by the operon d. continuous transcription of the operon's genes

Key Concepts

Inducible Operon

An inducible operon is a type of genetic regulatory system that is typically off but can be activated in response to an inducer molecule. In this system, the presence of a specific substrate or signal leads to the inactivation of a repressor protein, allowing RNA polymerase to transcribe the genes necessary for metabolizing that substrate. This mechanism is crucial for the efficient use of resources by the cell.

Repressor Protein

A repressor protein is a regulatory protein that binds to the operator region of an operon, blocking RNA polymerase from transcribing the downstream genes. In the case of an inducible operon, the repressor is usually bound to the operator until an inducer molecule is present, which causes a conformational change in the repressor, preventing it from binding to the operator and allowing gene expression to occur.

Gene Transcription Regulation

Gene transcription regulation refers to the mechanisms that control the rate and timing of gene expression. In prokaryotes, this often involves operons, where the binding of repressors or activators to specific DNA sequences can either inhibit or promote transcription. Understanding these regulatory mechanisms is essential for predicting the effects of mutations, such as a repressor that cannot bind to the operator, which would lead to continuous transcription of the operon's genes.