Hello, for enzymes you should take the unit of activity per milligram of protein.

For this, enzyme activity that you have should be divided into protein content in the sample. Then you can recalculate the enzyme activity based on protein amount.

Finally, you need the amount of protein that able to convert your substrate (μmol or g) to the product in specified conditions within 1min,

which says also the definition of enzyme activity.

An enzyme activity unit is a unit of enzyme's catalytic activity. 1 U (μmol/min) is defined as the amount of the enzyme that catalyzes the conversion of one micromole of substrate per minute under the specified conditions of the assay method.

A unit (U) in enzymology terms is 1 micromole of product formed per minute (also, confusingly, the amount of enzyme required to produce that amount of product). The starch substrate may be added to the reaction in grams/L because starch does not have a defined molecular weight. The product, glucose, however, can be measured in micromolar concentration units by employing a standard curve of micromolar glucose concentrations versus absorbance measurements. Use this standard curve to convert your absorbance measurements to glucose concentrations in micromolar. Multipy by the reaction volume in liters to get to micromoles. Divide by the reaction time in minutes to get micromoles/minute.

Make sure you are measuring the initial rate of the reaction. To be sure of this, you should make a plot of absorbance versus time for the reaction. The initial rate is determined by a line starting at time zero and running tangent to the early time points. The reaction may slow down at later time points, so do not include them in the rate measurement.

One of the information that should be written on your enzyme container is :

Each Unit equal to x gram so that you can calculate it.....

Hello, for enzymes you should take the unit of activity per milligram of protein.

For this, enzyme activity that you have should be divided into protein content in the sample. Then you can recalculate the enzyme activity based on protein amount.

Finally, you need the amount of protein that able to convert your substrate (μmol or g) to the product in specified conditions within 1min,

which says also the definition of enzyme activity.

An enzyme activity unit is a unit of enzyme's catalytic activity. 1 U (μmol/min) is defined as the amount of the enzyme that catalyzes the conversion of one micromole of substrate per minute under the specified conditions of the assay method.

If you know Specific activity (U of enzume/ protein mg) for your enzyme.. So you know the number of enzyme unite the found in each mg of protein.

Following

Enzyme units are usually expressed as µmol substrate converted per minute. If the question gives enzyme activity in nmol/min, divide by 1000 to convert to µmol. Then you multiply by the volume to obtain the total number of units.

https://www.mvls.gla.ac.uk/Teaching/SLS-GMC/enz1.html

Hi dear. you can prepare a stock solution of this enzyme in a nmol unit then divided by 1000 to convert to µmol then X volume=units

Following. Nice discussion.

In enzymology the international unit (IU) terms is 1 micromole of product formed per minute (the amount of enzyme required to produce that amount of product). Substrate may be added to the reaction in grams/L because starch does not have a defined molecular weight. The product, for example glucose, however, can be measured in micromolar concentration units by employing a standard curve of micromolar glucose concentrations versus absorbance measurements. Use this standard curve to convert your absorbance measurements to glucose concentrations in micromolar. Multipy by the reaction volume in liters to get to micromoles using molecular weight of glucose. Divide by the reaction time in minutes to get micromoles/minute.

As mentioned by : Dr. Adam B Shapiro

Make sure you are measuring the initial rate of the reaction.

In addition Specific activity: is U of enzume/ protein mg for your enzyme.. It means number of enzyme unite that found in each mg of protein.

enzyme activity that you have should be divided into protein content in the sample. Then you can recalculate the enzyme activity based on protein amount.