A 50 mL crude extract of skeletal muscle contains 32 mg of protein per mL. Ten microliter of the extract catalyzes a reaction at a rate of 0.14 micromol product formed per minute. The extract was frationated by ammonium sulfate precipitation, and the fraction precipitating between 20% and 40% saturation was redissolved in 10 mL. This soluction contains 50 mg/mL protein. Ten microliters of this purified faction catalyzes the reation at a rate of 0.65 micromol/min.
a) what is the degree of purification (fold purification)?
b) what is the percent yield of the enzyme recovered in the purified fraction?