Question

Enzyme Kinetics - Farrell/Taylor 133 3. Enzyme X has a molecular weight of 48,000. It converts substrate Z into product Y. Z absorbs at 340 nm, and Y absorbs at 480 nm. a. At what wavelength do you measure the change in absorbance to assay for enzyme X? Does the absorbance increase or decrease over time? b. If Vmax = 60 pmol/min and you use 400L of a 0.1 mg/mL solu- tion of enzyme, what is the turnover number? 4. Why is Vmax not a constant? Why do we want to analyze kcat instead of V max?

Answer 1

Amswev: 3a) we ton Mobuve tht disappearonte g z at 340 nmm CAbsovbomce will decvioase), or we Con Muobuve thi mirase y at 480n CAblorbanie oiU miriase) this will mot mosure the mymme,but will mosuve the engyme Actvity Vmax B Turm ovLY numbey Et Vmar is the maximum velolity ond Et is total emount d tm3yme imar = 0.4ml y0.1 mg/mL 0.04mg enymme Et C4o0ul-0.4mL) (6Olomol/aim)/(o.04g) Turm over number 15oo umol Turm overnumber

Vocar i dependut on the in3 ym Conlentvatiom ond Substrate Contutrotiom, which thonges duvimg the time Couvse is undepundut d any lontutratom ond tot So is a Cons tont