• 2022-06-01
    When only glucose is available to E. coli in the culture medium:  ( )
    A: cAMP-CAP is bound to the promoter;
    B: cAMP-CAP is not bound to the promoter;
    C: The repressor is not bound to the operator;
    D: The lac operon is turn on 
  • B

    内容

    • 0

      The operator is A: Another name for the terminator of a gene B: A DNA site bound by repressor proteins C: A protein that coordinates gene expression D: A part in the leader region of mRNA

    • 1

      Operator: ( ) A: An operator is a DNA region that is working with promoter for genes to express. B: An operator is a DNA region at 5’ of a gene for a repressor to bind to prevent gene expression. C: An operator is a repressor protein to help genes to express. D: An operator is a repressor protein to inhibit genes to express.

    • 2

      能与阻遏蛋白相结合的调控序列,叫做 A: RBS B: operon C: promoter D: operator E: SD序列

    • 3

      以下关于cAMP对原核基因转录的调控作用的叙述错误的是() A: cAMP可与分解代谢基因活化蛋白(CAP)结合成复合物 B: cAMP-CAP复合物结合在启动子前方 C: 葡萄糖充足时,cAMP水平不高 D: 葡萄糖和乳糖并存时,细菌优先利用乳糖 E: cAMP-CAP对乳糖操纵子的调节属于正性调节

    • 4

      以下关于cAMP对原核基因转录的调控作用的叙述不正确的是()。 A: 葡萄糖和乳糖并存时,细菌优先利用乳糖 B: cAMP可与分解代谢基因活化蛋白(CAP)结合成复合物 C: 葡萄糖充足时,cAMP水平不高 D: cAMP-CAP复合物结合在启动子前方 E: cAMP-CAP对乳糖操纵子的调节属于正性调节