An enzyme-catalyzed reaction produces a product that has a maximum absorbance at
ID: 58438 • Letter: A
Question
An enzyme-catalyzed reaction produces a product that has a maximum absorbance at 412nm. The extinction coefficient is 4000M^-1cm^-1, A l0 to-l dilution of the enzyme is made and 20 u.L of the dilution are put into a cuvette with 80 ul of water and l.9mL of reaction cocktail. The absorbance change per minute is 0.05.
a. How many units are in the cuvette if 1 U = 1 umol/min?
b. How many units are in the cuvette if 1 U = nmol/min?
c. What is the relative activity of the undiluted enzyme (1U =1 umol/min)?
PLEASE show the steps, don't just give me the answer, I have to understand this stuff! Thank you!
Explanation / Answer
Max. absorbance = 412 nm
extinction coefficient is 4000M^-1cm^-1
Dilution of enzyme = 2 ul
Water = 80 ul
Cocktail = 1.9 ml
A) The cuvettes are 1 cm in diameter
U = U/mL /mg/ml = 80/20 = 4 U/mg
C) Relative activity = unit/mL = U/mL
20/1.9 = 10.5 U/ml