When Enzymes are Purified, the Assay is Often Based On

Question

When enzymes are purified, the assay is often based on:
A) light absorbance.
B) catalytic activity.
C) pH.
D) temperature changes.
E) mRNA levels.

Accepted Answer

Enzymes are proteins that catalyze chemical reactions. Therefore, the most direct and commonly used method to quantify enzyme activity is to measure its catalytic activity. This can be done by monitoring either the disappearance of the substrate or the appearance of the product over time. Other methods such as light absorbance, pH or temperature changes may be used in conjunction with assays to optimize enzyme activity or to uncover potential effectors or inhibitors, but they are not sufficient on their own to estimate enzyme activity. mRNA levels are indicative of gene expression levels but are not directly linked to enzyme activity.