In the B-galactosidase assay, it is important to measure the density of E. coli cells because Select one:

a. the lac operon is induced only in a small percentage of cells in a culture.

b. the transformation efficiency of E. coli cells is low.

c. E. coli densities vary among cultures and with time, which will affect estimates of b-galactosidase production rates.

d. ONPG production by E. coli is a function of cell density.

e. we are measuring per cell cleavage of X-gal in relation to culture conditions and time.

Question

Aryan Mayer

Biology

4 September, 06:29

In the B-galactosidase assay, it is important to measure the density of E. coli cells because Select one:

a. the lac operon is induced only in a small percentage of cells in a culture.

b. the transformation efficiency of E. coli cells is low.

c. E. coli densities vary among cultures and with time, which will affect estimates of b-galactosidase production rates.

d. ONPG production by E. coli is a function of cell density.

e. we are measuring per cell cleavage of X-gal in relation to culture conditions and time.

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Answers (1)

Know the Answer?

Koen Cherry · Answer 1

Option C, E. coli densities vary among cultures and with time, which will affect estimates of b-galactosidase production rates.

Explanation:

The activity of β-galactosidase depends on the optical density or the intensity of the color.

In regards to color, yellow color intensity signifies the qualitative parameter of the β-galactosidase activity while the readings obtained through colorimeter is quantitative parameter of the β-galactosidase activity. In the presence of lactose, the gene responsible for producing β-galactosidase in E. coli is either induced or switched off.

Hence, option D is correct