1 Describe how you will prepare 30mls of a 004gL working enz

1. Describe how you will prepare 30mls of a 0.04g/L working enzyme (invertase) solution in 0.05M phosphate buffer (pH 7). 4g/L stock solution and the phosphate buffer are provided.

2. Describe how you will prepare 50mls of 50g/L and 50mls of 5g/L sucrose solutions in ddH20. A 200g/L sucrose stock solution provided.

Solution

Ans. #1. Using                       C1V1 (stock enzyme) = C2V2 (working soln.)

            Or, 4g L^-1 x V1 = 0.04 g L^-1 x 30 mL

            Or, V1 = (0.04 g L^-1 x 30 mL) / (4g L^-1)

            Hence, V1 = 0.30 mL

Thus, required volume of stock enzyme = 0.30 mL

# Preparation: To 0.30 mL stock enzyme taken in a sterile 50-mL-tube, add 29.7 mL phosphate buffer. Gently mix to get a homogenous solution.

#2. #I. Using             C1V1 (stock sucrose) = C2V2 (working soln.)

            Or, 200 g L^-1 x V1 = 50 g L^-1 x 50 mL

            Or, V1 = (50 g L^-1 x 50 mL) / (200 g L^-1)

            Hence, V1 = 12.5 mL

Thus, required volume of stock sucrose = 12.5 mL

# Preparation: Take 12.5 mL of stock sucrose solution in a 50-mL-standard volumetric flask. Make the final volume up to the mark with deionized water. Gently mix to get a homogenous solution.

#II. Using                   C1V1 (stock sucrose) = C2V2 (working soln.)

            Or, 200 g L^-1 x V1 = 5 g L^-1 x 50 mL

            Or, V1 = (5 g L^-1 x 50 mL) / (200 g L^-1)

            Hence, V1 = 1.25 mL

Thus, required volume of stock sucrose = 1.25 mL

# Preparation: Take 1.25 mL of stock sucrose solution in a 50-mL-standard volumetric flask. Make the final volume up to the mark with deionized water. Gently mix to get a homogenous solution.