A 25mM solution of dopamine is diluted 1 in 6. The diluted dopamine solution was used for a tyrosinase assay?

Question

A 25mM solution of dopamine is diluted 1 in 6. The diluted dopamine solution was used for a tyrosinase assay that had a total volume of 2mL. 200μL of tyrosinase was used for the assay. The reaction was followed spectrophotometrically and a progress curve plotted from the spectrophotometric data. Using the progress curve, the initial velocity was calculated as 0.24 ΔA/min.

The assay was repeated as above, except that 100μL of tyrosinase was used. What would the initial velocity be in this assay? Express your answer in ΔA/s (do not include units in the answer you type).

Answer 1

In the repeat assay the volume of tyrosinase is halved. When the volume of the tyrosine was halved, its concentration in the solution was also halved. Because the dopamine is in excess, the initial rate of reaction is proportional to the concentration of the tyrosinase. Because the concentration was halved, the intial rate of reaction was halved. So:



0.24 ΔA/min / 2 = 0.12 ΔA/min



New intial velocity (rate of reaction) = 0.12 ΔA/min

Answer 2

It depends on many factors

Answer 3

what a good question