1.0 ml of a preparation of the enzyme glucoamylase was added to 9 ml of a starch solution to give a final enzyme protein and starch concentrations of 0.8 mg protein/ml and 4 %wt. respectively and a pH 4.5 and temperature 60 degree C. If initial rate experiments show that the glucoamylase catalyses the production of 0.6 mu mol of glucose/ml-min, calculate the specific activity of the glucoamylase preparation.