One enzyme unit is defined as the amount of enzyme that causes the disappearance of 1 µmol (or µEq) of substrate, or appearance of 1 µmol (or µEq) of product, per minute: 1 e.u. = 1 µmol min-1. Or, one unit of any enzyme is that amount that will do a transformation of one micromole of substrate per minute under specific condition. Enzyme activity = "µmol of product" /"Time" = "disappearance of 1 µmol (or µEq) of substrate" /"Time" Calculation method of Vo depends upon mainly which enzyme you are using and which experimental method you are following. You can calculate Vo by measuring the disappearance of 1 µmol (or µEq) of substrate, or appearance of 1 µmol (or µEq) of product, per minute. First make standard curve of substrate or product with different concentration (Substarte or product concentration vs absorbance graph) . Then convert absorbance value after enzyme treatment with substrate following the standard method whatever you are using. I am sharing 3 other videos regarding amylase activity determination. Watch those videos and then you will get an idea how to calculate enzyme activity. 1. Making of a Standard Curve of Maltose || DNS Method (Miller, 1959) || Enzymes 19 (youtube.com) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Lx5TDE1paGA.html 2. How to Create a Linear Standard Curve of Maltose in Excel ? || DNS method || Enzyme 20 (youtube.com) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Vnr1oM6OY0g.html 3. Determination of 𝛼-Amylase Activity using Standard Curve of Maltose || DNS Method || Enzymes 21 (youtube.com) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8cPxz2NXYS4.html
You have to know initial velocity of the reaction that means rate of the reaction. Rate of the reaction you can measure by estimating product formation per unit time that means product concentration/incubation time of the reaction. otherwise, you can measure rate of decrease of substrate concentration that is also reaction velocity. you can check following videos to know how to measure enzyme activity or rate of the enzyme catalyzed reaction: Making of a Standard Curve of Maltose || DNS Method (Miller, 1959) || Enzymes 19 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Lx5TDE1paGA.html How to Create a Linear Standard Curve of Maltose in Excel ? || DNS method || Enzyme 20 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Vnr1oM6OY0g.html
