Answer:
The correct option is: A. activity; concentration
Explanation:
A reaction rate essay is a laboratory method to determine the activity of an enzyme. It is necessary for determining the enzyme kinetics and inhibition.
Whereas, a colorimetric analysis is a method to determine the concentration of a chemical compound in a solution. Therefore, a colorimetric endpoint assay measures the concentration.
Therefore, Enzyme activity is measured by a reaction rate assay and the concentration is measured by a colorimetric endpoint assay.
