객관식
The protein that binds to the operator of the lac operon to prevent transcription is encoded by which gene?
4134
views
16
rank
15. Central Dogma & Gene Regulation
The Lac Operon
1:39분문제 10
교과서 질문
For the lactose operon to be “on” and actively transcribed, ___________ must be present and ___________ must be absent.
검증된 단계별 안내1
Understand the lactose operon system: It is a set of genes involved in the metabolism of lactose in bacteria, primarily E. coli. The operon is regulated by the presence or absence of lactose and glucose.
Identify the role of the inducer molecule: Lactose (or its isomer allolactose) acts as the inducer that binds to the repressor protein, causing it to change shape and release from the operator region, allowing transcription to proceed.
Recognize the role of the repressor protein: The repressor binds to the operator to block transcription when lactose is absent. For the operon to be 'on,' the repressor must not be bound to the operator, which means it must be inactive or absent from the operator site.
Consider the effect of glucose presence: When glucose is present, it inhibits the activation of the operon by lowering cyclic AMP (cAMP) levels, which are necessary for the cAMP receptor protein (CRP) to bind and activate transcription. Therefore, glucose must be absent or at low levels for the operon to be fully active.
Summarize the conditions for the operon to be 'on': Lactose (or allolactose) must be present to inactivate the repressor, and glucose must be absent to allow cAMP-CRP complex formation and activation of transcription.
비슷한 문제에 대한 검증된 영상 답변:이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Lactose Operon Structure and Function
The lactose operon (lac operon) is a set of genes in bacteria that enables the metabolism of lactose. It includes structural genes, a promoter, an operator, and regulatory elements that control transcription based on environmental signals.
추천 영상:
04:23
Structure of an Operon
Role of Allolactose (Inducer) in Operon Activation
Allolactose, a derivative of lactose, acts as an inducer by binding to the lac repressor protein, causing it to change shape and detach from the operator. This removal allows RNA polymerase to transcribe the operon genes.
추천 영상:
04:25Inducible Operons
Function of the Lac Repressor Protein
The lac repressor is a protein that binds to the operator region of the lac operon to block transcription when lactose is absent. Its absence from the operator is necessary for the operon to be 'on' and actively transcribed.
추천 영상:
07:06The Lac Operon
관련 영상
관련 실천