Enzyme Activity Calculator

Calculate enzyme activity from spectrophotometric data -- the most common calculation in IBO practical exams. Combines Beer-Lambert law with activity computation.

IBO Exam Presets

1. Beer-Lambert Law

Calculate concentration from absorbance

Absorbance (A)

Path length, l (cm)

Extinction coeff. preset

Epsilon (mM⁻¹ cm⁻¹)

Concentration

2. Enzyme Activity

Calculate activity in U/mL (one Unit = 1 micromol substrate converted per minute)

Delta-A (change in absorbance)

Delta-t (time interval)

Time unit

V_total (total assay vol., mL)

V_enzyme (enzyme vol., mL)

Epsilon (mM⁻¹ cm⁻¹) -- auto-filled from Section 1

Enzyme Activity

3. Specific Activity (optional)

Normalize by protein concentration (e.g. from Bradford assay)

Protein concentration (mg/mL)