Repressible operons typically code for proteins needed to make products required for cellular pathways. When the cell requires the product of this operon, this operon will be expressed. But once the product is accumulated in the cell, it binds the repressor of the operon and the operon is repressed or turned off. This regulates the amount of products in the cell through gene regulation and expression. 

Repressible Operons

Inducible operons typically encode proteins that use or break down specific molecules in the cell. Their expression is induced when in the presence of that molecule so that the operon is only expressed when the genes are needed to break down that compound.

Inducible Operons

Operons are a section of genes that are all transcribed together. The operon is regulated by the promoter and operator sequence upstream of the genes in the operon. Operons are found primarily in prokaryotes.

University of Wisconsin - Madison

Gene expression must be regulated in order to express the genes that are needed at the right times so that cellular energy is not wasted. There are many regulatory genes required for gene regulation in eukaryotes and prokaryotes.

Gene Regulation

https://openstax.org/details/books/microbiology/

Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology’s art program enhances students’ understanding of concepts through clear and effective illustrations, diagrams, and photographs.

Microbiology is produced through a collaborative publishing agreement between OpenStax and the American Society for Microbiology Press. The book aligns with the curriculum guidelines of the American Society for Microbiology.

OpenStax Microbiology Textbook

Operon

Transcription factors are proteins that regulate genes by binding to DNA. They typically bind upstream of an operon to regulate its expression. They can be repressors and prevent RNA Polymerase from transcribing genes or activators and facilitate the binding of RNA Polymerase to transcribe genes. They respond to stimuli in the cell's environment to regulate genes.

Transcription Factors

Promoter sequences are DNA sequences that define where transcription of a gene by RNA polymerase begins. Transcription factor activators can also interact with this sequence to activate transcription. Promoter sequences are typically located directly upstream of the genes they regulate. 

Promoter

An operator is the DNA sequence that is usually downstream of the RNA Polymerase binding site but upstream of the first gene in the operon. The operon interacts with a transcriptional repressor. By binding to the operator sequence, repressors physically block the RNA Polymerase from interacting with the -10 and -35 sequences to transcribe.

Learn Before

Related

Learn After