An increase in Beta-galactosidase occurs in E. coli cells in response to an increase in which effector molecule A. Galaktose / Galactose B. Glukose / Glucose C. Laktose / Lactose D. Allolaktose / Allolactose

The effect of an antibiotic on the expression of β-galactosidase was studied in E. coli. Bacteria were cultured in the presence of an established lac inducer, with or without the antibiotic. After lysis, the samples were incubated with a chromogenic β-galactosidase substrate. Finally, the amount of the coloured product formed was detected by photometry. The table below shows the O.D. values of different samples. Which antibiotic was used?

Catabolite repression in E. coli primarily demonstrates how:Question 3Answera.The presence of glucose enhances the utilization of lactose.b.Lactose can increase the cAMP levels in the cell.c.Glucose presence inhibits lactose metabolism.d.Glucose and lactose are metabolized simultaneously.

Which of the following is the inducer of the lac operon in cells? Group of answer choiceslactose allolactosegalactoseglucoseisopropylthiogalactopyranoside

"It seems that the existence of a higher coliform population encoding just for the b-galactosidase enzyme leads to higher enumerations of coliforms using the Colilert method (Schets et al. 2001)" explain this extract.

4. What molecule serves as an inducer of the lac operon?a) Lactosec) Allolactoseb)e) laclGlucosed) Galactose