Introduction 1.1 Aim: To determine the kinetic parameters, Vmax and Km, of the alkaline phosphatase enzyme through the determination of the optimum pH and temperature. 1.2 Theory and Principles (General Background): Enzymes are highly specific protein catalysts that are utilised in chemical reactions in biological systems.1 Enzymes, being catalysts, decrease the activation energy required to convert substrates to products. They do this by attaching to the substrate to form an intermediate; the substrate binds to the active site of the enzyme. Then, another or the same enzyme reacts with the intermediate to form the final product.2 The rate of enzyme-catalysed reactions is influenced by different environmental conditions, such as: concentration …show more content…
Use these results to determine the product concentration, using Beer-Lambert’s Law: A= ɛCl (where A is the absorbance, ɛ is the molar absorptivity, C is the product concentration and l is the length of solution that the light passes through). Calculate the product concentrations at every minute for 10 minutes for all 7 of the test tubes using Beer-Lambert’s Law. Plot a graph of product concentration vs. time and then use the gradients of the 7 test tubes to determine the velocities of the reaction. After calculating the velocities, plot a Michaelis-Menten graph of velocity vs. substrate concentration. Predict/ roughly determine the Vmax and ½ Vmax values from the peak of the graph, where the slope of the graph levels off (the asymptotical line). Predict/ roughly determine the Km by reading off of the graph the corresponding substrate concentration on the x-axis for the ½ Vmax value. Plot a Lineweaver-Burke graph (the inverse of the velocity of the reaction vs. the inverse of the substrate concentration). Calculate accurate Vmax and Km values using the following equation for the Lineweaver-Burk