Enzyme Activity / Specific Activity Calculator
Calculate total enzyme activity in Units (U), volume activity (U/mL), and specific activity (U/mg protein) from spectrophotometric rate measurements.
Input Parameters
Enter details for calculation.
Enzyme Concentration Activity
Specific Activity
Expert Tip
One Unit (U) is defined as the amount of enzyme that catalyzes the conversion of 1 micro-mole of substrate per minute under standard conditions.
Calculation Methodology & Details
Formula
The extinction coefficient ε should be entered in mM⁻¹ cm⁻¹. If using substrate extinction in M⁻¹, divide it by 1,000 to convert to mM⁻¹.
Important Disclaimer
The calculations provided are for educational and general planning guidelines only. They do not replace professional laboratory or environmental analysis or certified scientific advice.
How to Calculate Specific Activity
Follow these steps to analyze enzyme kinetics spectrophotometrically:
Determine rate
Obtain the change in absorbance per minute (ΔA/min) from the linear slope of your assay.
Enter parameters
Input cuvette pathlength, extinction coefficient, assay volume, and enzyme sample volume.
Normalize to Protein
Provide protein concentration (mg/mL) to convert volumetric activity to specific activity.