This document discusses the use of enzymes in therapy. It provides examples of enzymes that are used to treat various disorders, such as DNase 1 to treat cystic fibrosis by reducing mucus viscosity, lipase to treat Gaucher's disease by breaking down lipid accumulations, and streptokinase to treat heart attacks by breaking down blood clots. The document also discusses the criteria for enzymes used in therapy, such as having low Km and high Vmax, and being purified and specific. Enzyme replacement therapy is described as a treatment for lysosomal storage diseases where the deficient enzyme is replaced.