Life Sciences Numeracy Resource
Enzymes
This type of question starts with the experimental data collected in an enyme assay: the amount of substrate converted to product per minute. (This is generally calculated from spectrometric measurements using extinction coefficients or standard curves.) The task is to convert this into the total number of international enzyme units present, taking into account the volume of the assay. An enzyme unit is defined as the enzyme activity that catalyses the conversion of 1 µmol substrate into product in one minute.

Enzyme units: