Multiple Choice
Based on the information you know about the trp operon, is the creation of tryptophan expensive to the cell?
15. Central Dogma & Gene Regulation
The Trp Operon
Struggling with Microbiology?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
If the trp regulatory gene mutates so that the repressor protein can no longer bind to tryptophan what will be the result?
A
The trp operon will not be expressed.
B
The trp operon will be continuously expressed.
C
The trp operon will be expressed in the presence of tryptophan only.
D
The trp operon will be expressed in the absence of tryptophan only.
E
There will be no effect on the trp operon.
Verified step by step guidance1
Understand the role of the trp operon: The trp operon in E. coli is responsible for the synthesis of tryptophan. It is typically repressed when tryptophan is abundant in the environment.
Identify the function of the repressor protein: The repressor protein binds to the operator region of the trp operon to inhibit transcription when tryptophan is present. Tryptophan acts as a corepressor by binding to the repressor protein, enabling it to attach to the operator.
Consider the mutation's effect: If the regulatory gene mutates such that the repressor protein can no longer bind to tryptophan, the repressor cannot be activated by tryptophan.
Analyze the consequences of the mutation: Without the ability to bind tryptophan, the repressor protein remains inactive, regardless of tryptophan levels. This means it cannot bind to the operator to block transcription.
Conclude the outcome: As a result, the trp operon will be continuously expressed because the repressor cannot inhibit its transcription, even in the presence of tryptophan.
Related Videos
Related Practice
