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Which of the following is incorrect for tryptophan operon?
- a)The operon operates by a negative repressible feedback mechanism
- b)Repression and attenuation are the two mechanisms involved
- c)Repressor binds to the operator in the presence of Trp
- d)Repressor binds to the operator in the absence of Trp
Correct answer is option 'D'. Can you explain this answer?
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Verified Answer
Which of the following is incorrect for tryptophan operon?a)Theoperon ...
All the statements regarding tryptophan operon are correct, except statement (d) i.e. repressor binds to the operator in absence of tryptophan. Actually, when tryptophan is present in the medium, it binds to the repressor, changes its conformation and recruits it onto the operator, thereby stopping the expression of tryptophan operon.
Most Upvoted Answer
Which of the following is incorrect for tryptophan operon?a)Theoperon ...
Incorrect statement: Repressor binds to the operator in the absence of Trp (tryptophan).
Explanation:
The tryptophan operon is a group of genes in bacteria that are involved in the synthesis of the amino acid tryptophan. The regulation of these genes is controlled by a repressor protein that binds to the operator region of the operon.
Operon mechanism:
The tryptophan operon operates by a negative repressible feedback mechanism. This means that the repressor protein is synthesized in an inactive form and only becomes active when bound to tryptophan. The presence or absence of tryptophan in the cell determines the activity of the repressor protein and subsequently the expression of the genes in the operon.
Mechanisms involved:
Repression and attenuation are the two mechanisms involved in the regulation of the tryptophan operon.
1. Repression: In the presence of tryptophan, tryptophan molecules bind to the inactive repressor protein, causing it to change its conformation and become active. The active repressor protein then binds to the operator region of the operon, preventing the transcription of the genes. This is a negative regulation mechanism as it inhibits gene expression.
2. Attenuation: Attenuation is a regulatory mechanism that occurs during transcription. It involves the premature termination of transcription depending on the availability of tryptophan in the cell. In the absence of tryptophan, the ribosome translating the mRNA can proceed without interruption, allowing the full operon to be transcribed. In the presence of tryptophan, the ribosome stalls at a specific region of the mRNA called the attenuator sequence, leading to premature termination of transcription. This mechanism allows the cell to adjust the amount of tryptophan synthesis based on the availability of tryptophan in the environment.
Conclusion:
The incorrect statement is option D, where it states that the repressor binds to the operator in the absence of tryptophan. In reality, the repressor binds to the operator in the presence of tryptophan, leading to the repression of gene expression.
Explanation:
The tryptophan operon is a group of genes in bacteria that are involved in the synthesis of the amino acid tryptophan. The regulation of these genes is controlled by a repressor protein that binds to the operator region of the operon.
Operon mechanism:
The tryptophan operon operates by a negative repressible feedback mechanism. This means that the repressor protein is synthesized in an inactive form and only becomes active when bound to tryptophan. The presence or absence of tryptophan in the cell determines the activity of the repressor protein and subsequently the expression of the genes in the operon.
Mechanisms involved:
Repression and attenuation are the two mechanisms involved in the regulation of the tryptophan operon.
1. Repression: In the presence of tryptophan, tryptophan molecules bind to the inactive repressor protein, causing it to change its conformation and become active. The active repressor protein then binds to the operator region of the operon, preventing the transcription of the genes. This is a negative regulation mechanism as it inhibits gene expression.
2. Attenuation: Attenuation is a regulatory mechanism that occurs during transcription. It involves the premature termination of transcription depending on the availability of tryptophan in the cell. In the absence of tryptophan, the ribosome translating the mRNA can proceed without interruption, allowing the full operon to be transcribed. In the presence of tryptophan, the ribosome stalls at a specific region of the mRNA called the attenuator sequence, leading to premature termination of transcription. This mechanism allows the cell to adjust the amount of tryptophan synthesis based on the availability of tryptophan in the environment.
Conclusion:
The incorrect statement is option D, where it states that the repressor binds to the operator in the absence of tryptophan. In reality, the repressor binds to the operator in the presence of tryptophan, leading to the repression of gene expression.
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Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer?
Question Description
Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? for IIT JAM 2024 is part of IIT JAM preparation. The Question and answers have been prepared according to the IIT JAM exam syllabus. Information about Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for IIT JAM 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer?.
Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? for IIT JAM 2024 is part of IIT JAM preparation. The Question and answers have been prepared according to the IIT JAM exam syllabus. Information about Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for IIT JAM 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer?.
Solutions for Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for IIT JAM.
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Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of Which of the following is incorrect for tryptophan operon?a)Theoperon operates by a negative repressible feedback mechanismb)Repression and attenuation are the two mechanisms involvedc)Repressor binds to the operator in the presence of Trpd)Repressor binds to the operator in the absence of TrpCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
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