What is the fundamental difference between the repressor protein in a repressible operon versus the repressor protein in an inducible operon?
a. The repressor protein in a repressible operon is usually active and binds to the operator, blocking transcription, whereas the repressor protein in an inducible operon is usually inactive and only binds to the operator in the presence of a specific inducer molecule.
b. The repressor protein in a repressible operon is typically synthesied in response to a specific corepressor molecule, which activates it to bind to the operator, while the repressor protein in an inducible operon is usually constitutively synthesied but can be inactivated by a specific inducer molecule.
c. In a repressible operon, the repressor protein acts to continuously block transcription unless a specific corepressor is present, while in an inducible operon, the repressor protein acts to continuously allow transcription unless a specific inducer is present.
d. The repressor protein in a repressible operon is usually part of a feedback loop that helps regulate the production of a particular molecule, while the repressor protein in an inducible operon is usually involved in responding to external stimuli to regulate gene expression.