Skip to main content
Ch. 7 - Microbial Genetics
Bauman - Microbiology with Diseases by Taxonomy 6th Edition
Bauman6th EditionMicrobiology with Diseases by TaxonomyISBN: 9780134832302Non è quello che usi tu?Cambia libro di testo
Capitolo 7, Problema 21

Repressible operons are important in regulating prokaryotic:
a. DNA replication
b. RNA transcription
c. rRNA processing
d. Sugar catabolism

Guida verificata passo dopo passo
1
Understand the concept of a repressible operon: it is a type of operon in prokaryotes that is usually active but can be turned off (repressed) when a specific molecule, often the end product of a metabolic pathway, is present.
Recall that operons regulate gene expression primarily at the level of RNA transcription by controlling whether RNA polymerase can transcribe the genes in the operon.
Identify that repressible operons typically control biosynthetic pathways, where the end product acts as a corepressor to inhibit transcription when it is abundant.
Evaluate the options: DNA replication is not regulated by operons; rRNA processing is a post-transcriptional modification; sugar catabolism is often regulated by inducible operons, not repressible ones.
Conclude that repressible operons are important in regulating RNA transcription, making option (b) the correct focus.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
2m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Repressible Operons

Repressible operons are gene clusters in prokaryotes that are usually active but can be turned off (repressed) when a specific molecule, often the end product of a metabolic pathway, is abundant. This regulation helps conserve resources by stopping the synthesis of enzymes no longer needed.
Video consigliato:
03:42
Repressible Operons

Regulation of RNA Transcription

Operons control gene expression primarily at the transcriptional level by regulating RNA polymerase activity. In repressible operons, a repressor protein binds to the operator region to block RNA transcription when the corepressor is present, preventing mRNA synthesis.
Video consigliato:
01:56
Eukaryotic Post-Transcriptional Regulation

Metabolic Pathways and Gene Regulation

Repressible operons often regulate genes involved in biosynthetic pathways, such as amino acid synthesis, where the end product acts as a corepressor. This feedback mechanism ensures that enzymes for producing a metabolite are only made when needed, optimizing cellular efficiency.
Video consigliato:
00:53
Prokaryotic Gene Regulation via Operons