A repressible operon turned off when tryptophan accumulates and activates the repressor.
Tryptophan acts as a corepressor: when it is plentiful it binds the repressor and enables it to block transcription. Attenuation adds further control by terminating transcription early if charged tRNA-Trp is abundant.
Anabolic pathways are typically repressible, catabolic ones inducible.
A repressible operon turned off when tryptophan accumulates and activates the repressor.
Trp Operon is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Lac Operon, Operon, Transcription Factors.
E. coli stops making tryptophan when it grows in a rich medium.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Trp Operon. Intermediate topics assume the Beginner vocabulary.
The closest topics to Trp Operon are Lac Operon, Operon, Transcription Factors, Riboswitches. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Trp Operon. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Trp Operon: A repressible operon turned off when tryptophan accumulates and activates the repressor. Lac Operon: An inducible bacterial operon switched on when lactose is present and glucose is scarce. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Lac Operon and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
An inducible bacterial operon switched on when lactose is present and glucose is scarce.
🧫 Molecular BiologyA cluster of bacterial genes under one promoter and operator, regulated together.
🧫 Molecular BiologyProteins that bind specific DNA sequences to turn genes on or off.
🧫 Molecular BiologyRNA elements that bind small metabolites and change structure to regulate gene expression directly.
🧫 Molecular Biology