Chapter 2 – Introduction to enzyme kinetics

Publisher Summary This chapter describes enzymes kinetics. The rates of enzyme-catalyzed reactions were first studied in the latter part of the 19th century. Most of the early studies were concerned with enzymes from fermentation, particularly invertase, which catalyzes the hydrolysis of sucrose; the reaction is sucrose + water→ glucose + fructose. O'Sullivan and Tompson studied the reaction and they found that the reaction was highly dependent on the acidity of the mixture and that the rate was proportional to the amount of enzyme. The condition provided was that the acidity should be in the most favorable proportion. Brown placed the idea of an enzyme–substrate complex in a purely kinetic context. Brown placed the idea of an enzyme–substrate complex in a purely kinetic context. Michaelis and Menten controlled the pH of the reaction by the use of acetate buffers, they allowed for the muta-rotation of the product and they measured initial rates of the reaction at different substrate concentrations. For enzymes whose molar concentration cannot be measured, it is often convenient to define a unit of catalytic activity.