Question

Y LLLLLLILULUJ LLLLLLLLL metabolic conditions. c) The A420 data collected in the final week of this exercise is presented below. You need to fully explain the results obtained. Under what conditions is B-galactosidase activity observed? Be sure to relate the observations back to the GAL system in yeast. Table 3: Observed colour and absorbance at 420 nm for DY2389 (non-transformed) and DY2389/Pry121(transformed) cell free yeast extracts on various media. The Ion-transformed cells were inoculated into SD plus uracil tubes and the transformed cells were inoculated into SD #minus uracil tubes Sample Tube Contents Colour Absorbance DY2389 SD + Ura + galactose Clear 0.012 DY2389 SD + Ura + glucose Clear 0.005 DY2389/Pry121 SD - Ura + galactose Yellow 0.773 DY2389/Pry121 SD - Ura + glucose Clear 0.020

Answer 1

DY2389 both with glucose and galactose and DY2389Pry121 incubated with SD + Ura + glucose shows the beta-galactosidase activity since all three of them shows less absorbance means less protein product is formed due to More beta-galactosidase activity. Although DY2389prt121 show less activity than other two , it shows that transformation was not 100%.

DY2389/Pry121 shows no beta-galactosidase activity as absorbance is high due to high protein content.