Question

Allolactose, an isomer of lactose, is formed in small amounts from lactose. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose) as a potential food source. Which of the following occurs when the lactose enters the cell?A) The repressor protein attaches to the regulator.B) Allolactose binds to the repressor protein.C) Allolactose binds to the regulator gene.D) The repressor protein and allolactose bind to RNA polymerase.E) RNA polymerase attaches to the regulator.

Answer 1

RNA polymerase must bind to the promoter, and the repressor must be inactive. Allolactose, an isomer of lactose, is formed in small amounts from lactose. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose) as a potential food source.