Question

Showing each step: Use the molecular weight of Tyrosinase, 128,000, to determine how many micromoles of Tyrosinase are in the tubes. Assume 5 mL of Tyrosinase is used and that it has a concentration of 15 mg/mL.  

Answer 1

Given concentration of Tyrosinase is 15 mg/mL.  

That means 1 mL of the solution contains 15 mg of Tyrosinase

                  5 mL of the solution contains 15x5 = 75 mg of Tyrosinase

Given molecular weight of Tyrosinase =128,000 g/mol

We know that number of moles , n = mass/molar mass

                                                   = 75 mg / (128000 (g/mol))

                                                   = 75x10^-3 g / (128000 (g/mol))

                                                   = 5.47x10^-8 mol

                                                   = 5.47x10^-2x10^-6 mol

                                                   = 5.47x10^-2 micromol