She spent a lot of her time trying to purify enzymes because she was not satisfied with the commercial material .
During her time as a chemist , Caldwell did research on a type of enzyme called amylase .
Caldwell spent a lot of Caldwell 's time trying to purify enzymes because she was not satisfied with the commercial material .
During her time as a chemist , Caldwell did research on a type of enzyme called amylase .