Lac Operon Feedback & Glucose Effect — NEET Biology
📚 Practice ConceptIn the medium where E. coli was growing, lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium?
Which of the above statements are NOT correct regarding the regulation of the lac operon? S1: A deletion mutation in the i gene would typically lead to constitutive expression of the lac operon. S2: The presence of lactose in the medium ensures that the lac repressor remains bound to the operator, inhibiting transcription. S3: High levels of glucose in the growth medium generally lead to decreased transcription of the lac operon, even if lactose is present. S4: A non-functional repressor protein due to a mutation would result in continuous synthesis of lac operon enzymes. S5: When a functional repressor is bound to the operator sequence, RNA polymerase cannot effectively initiate transcription. S6: The lac operon is considered inducible because its expression is turned off in the presence of its substrate, lactose.
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