章节大纲

  • 常规

    全部折叠 展开全部

  • 蛋白质基因规范

    What will you learn
    ::你会学到什么

    • How is regulated in
      ::如何在
    • The role of operons in prokaryotic gene regulation
      ::支持者在蛋白质基因管制中的作用

    A light switch with 'ON' in black and 'Off' in black, indicating gene regulation.

    On or off?
    ::开还是关?

    When it comes to genes, that is an important question. And if you're a single-celled organism like a , conserving energy by not producing unnecessary is very important.
    ::当涉及到基因时,这是一个重要问题。如果你是一个单细胞生物,就像一个单一细胞生物,那么通过不生产不必要的能源来节能是非常重要的。

    Prokaryotic Gene Regulation
    ::蛋白质基因规范

    Transcription is regulated differently in prokaryotes and eukaryotes . In general, prokaryotic regulation is simpler than eukaryotic regulation.
    ::在 prokaryotes 和 eukaryotes 中,Transnation 管理方式不同。 一般来说, prokary 监管比 eukaryotes 监管简单。

    The Role of Operons
    ::Operons的作用

    Regulation of transcription in prokaryotes typically involves operons. An operon is a region of that consists of one or more genes that encode the proteins needed for a specific function. The operon also includes a promoter and an operator . The operator is a region of the operon where regulatory proteins bind. It is located near the promoter and helps regulate transcription of the operon genes.
    ::prokaryotes的转录规程通常涉及 porerons 。 角数是由一种或多种基因组成的区域,这些基因对特定功能所需的蛋白进行编码。 角数还包括一个促进者和操作者。 操作者是操作者所在的角数区域,其中调节蛋白质,它位于促进者附近,帮助调节角数基因的转录。

    The Lac Operon
    ::拉克·奥佩伦

    A well-known example of operon regulation involves the lac operon in E. coli bacteria (see the Figure and the video at the link below). The lac operon consists of a promoter, an operator, and three genes that encode the needed to digest lactose, the sugar found in milk. The lac operon is regulated by lactose in the environment. 
    ::操作规程的一个众所周知的例子涉及E. coli细菌中的 lac auderon (见下链接的图和视频 ) 。 Lac operon 包括一个促进者、一个操作员和三个基因,这三个基因编码了消化乳糖所需要的乳糖,即牛奶中发现的糖。 Lac operon 是由环境中的乳糖调节的。

    • When lactose is absent, a repressor protein binds to the operator. The operator is located between the promoter and the three lac operon genes. The protein blocks the binding of RNA polymerase to the promoter. As a result, the lac genes are not expressed.
      ::当乳糖不存在时, 抑制剂蛋白就会粘结到操作员身上。 操作员位于促进者与三种 lac pereron 基因之间。 蛋白质将RNA 聚合酶结合到促进者身上。 因此, Lac 基因不会被表达出来 。
    • When lactose is present, the repressor protein does not bind to the operator. This allows RNA polymerase to bind to the promoter and begin transcription. As a result, the lac genes are expressed, and lactose is digested.
      ::当乳糖存在时,抑制剂蛋白不会与操作员捆绑在一起。 这使得RNA聚合酶能够与促销者捆绑并开始转录。 结果, Lac 基因被表达出来,乳糖被消化。

    Why might it be beneficial to express genes only when they are needed? (Hint: synthesizing proteins requires energy and materials.)
    ::为什么只有在需要时才能表达基因才有益? (提示:合成蛋白质需要能量和材料。 )

    Lac operon structure showing promoter, operator, and genes lacZ, lacY, lacA.
    The three genes of the lac operon are lacZ, lacY, and lacA. They encode proteins needed to digest lactose. The genes are expressed only in the presence of lactose.

     

     

    Summary
    ::摘要

    • Regulation of transcription in prokaryotes typically involves an operon, such as the lac operon in E. coli .
      ::原虫的转录条例通常涉及意见书,如E. coli的lac 意见书。
    • The lac operon is regulated by proteins that behave differently depending on whether lactose is present or absent.
      ::乳糖阳极由蛋白质调节,蛋白质的行为因乳糖是否存在而不同。

    Review
    ::回顾

    1. What is an operon?
      ::什么是礼服?
    2. Why might it be beneficial to express genes only when they are needed?
      ::为什么只有在需要时才能表达基因才有益呢?
    3. What is the role of an operon's operator?
      ::执行官的操作员的作用是什么?
    4. What happens to the lac operon in the absence of lactose?
      ::在没有乳糖的情况下 乳糖的 Lac Operon会怎么样?
    5. Draw a diagram to show how the lac operon is regulated.
      ::绘制图表以显示 Lac 操作程序是如何管理的 。