how reaction rates of enzyme can be affected by factors including temp, ph, the presecne of inhibitors and concentrations of reactants and products]
The rate of an enzyme-catalyzed reaction can be affected by several factors including temperature, pH, the presence of inhibitors, and concentrations of reactants and products.
1. Temperature - Enzymes have an optimal temperature at which they work best. This is because enzymes are proteins, and like other proteins, they are sensitive to high temperature. As temperature increases, enzyme activity also increases up to a point, called the optimum temperature. Beyond this point, the enzyme denatures and loses its function. Therefore, the rate of reaction of an enzyme-catalyzed reaction is directly proportional to the temperature until the optimum temperature is reached.
2. pH - Each enzyme has an optimum pH at which it works the most efficiently. This is because the pH affects the ionization state of the amino acids present in the enzyme. With a change in pH, the enzyme may become denatured and lose its function. Therefore, acidic or basic pH levels can affect the rate of the enzyme-mediated reaction.
3. Presence of inhibitors - Enzyme inhibitors are compounds that can reduce the activity of an enzyme. Inhibitors can be reversible or irreversible. Reversible inhibitors bind to the active site of the enzyme, preventing the substrate from binding. The rate of enzyme-mediated reaction decreases with the presence of inhibitors.
4. Concentration of reactants and products - The rate of enzyme-catalyzed reactions increases with an increase in substrate concentration, as more substrate is available for enzymes to bind. However, at a certain substrate concentration level, all enzymes are working at their maximum capacity, and any further increase in substrate concentration will not increase the rate of the reaction. The rate of reaction also decreases when the concentration of the product increases beyond a certain concentration level, as the product competes with the substrate for binding to the enzyme.