Acid phosphatase is present in many plant tissues where it catalyzes the removal of phosphate groups from macromolecules at low pH. In this exercise, students prepare a cell-free extract from wheat germ and determine the amount of the enzyme present in the extract. The experiment offers practical experience with enzyme extraction procedures and is an excellent introduction to the analysis of enzyme activity and basic enzyme kinetics.

A colorimeter is desirable but not absolutely necessary for this exercise.