1. What is Enzyme Activity?

Enzyme activity is a measure of the catalytic ability of an enzyme, typically expressed as the amount of substrate converted per unit time per milligram of enzyme. It's a crucial parameter in biochemistry and enzymology studies.

2. How Does the Calculator Work?

The calculator uses the enzyme activity equation:

Where:

• \( \Delta \text{Substrate} \) — Change in substrate concentration (mol)
• \( \text{Time} \) — Reaction time (minutes)
• \( \text{Enzyme Amount} \) — Amount of enzyme used (mg)

Explanation: The equation calculates how much substrate one milligram of enzyme can convert per minute under specified conditions.

3. Importance of Enzyme Activity Measurement

Details: Measuring enzyme activity is essential for characterizing enzymes, studying enzyme kinetics, determining enzyme purity, and assessing enzyme inhibition or activation.

4. Using the Calculator

Tips: Enter the change in substrate concentration in moles, reaction time in minutes, and enzyme amount in milligrams. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical units for enzyme activity?
A: Common units are μmol/min/mg (micromoles per minute per milligram) or U/mg (units per milligram), where 1 unit = 1 μmol/min.

Q2: How is Δ substrate measured?
A: Typically measured by spectrophotometry (absorbance change) or other analytical methods that track substrate disappearance or product appearance.

Q3: What affects enzyme activity measurements?
A: Temperature, pH, substrate concentration, presence of inhibitors or activators, and enzyme stability all affect measured activity.

Q4: Should reaction time be kept short?
A: Yes, initial velocity measurements (early in the reaction) are most accurate as they avoid complications from substrate depletion or product inhibition.

Q5: How can I convert to specific activity?
A: Specific activity is activity per milligram of protein, so if your enzyme preparation isn't pure, divide by total protein amount rather than enzyme amount.