Enzyme Lab Report

Enzymes are biological molecules macromolecules that catalyze chemical reactions. Enzymes are usually proteins; however, it has been discovered that some enzymes are RNA molecules. The molecules at the beginning of the process to which enzymes act upon are called substrates, which are converted to the products by the actions of the enzyme. Almost all metabolic processes require enzymes to catalyze reactions to a rate that is fast enough to sustain life. Enzymes increase the rate of the reaction by lowering the activation energy by providing an alternative reaction pathway. Metaphorically, enzymes lower the energy hill that a reaction must leap over in order for the reaction to proceed forward. The enzyme does this by orienting the substrates …show more content…
These are called enzyme inhibitors. The three main types of inhibitors include competitive, non-competitive, and mixed mode. A competitive inhibitor competes with the substrate in order to occupy the active site of the enzyme. This means that if the substrate concentration is increased, the chance that the inhibitor will bind to the enzyme is decreased. Therefore, if the concentration of the substrate is high enough, the enzyme can still be able to reach the same maximum velocity of the enzyme, Vmax, as without the inhibitor. However, when the inhibitor is present, a greater concentration of substrate is required to counter act the inhibitor and bring the velocity of the enzyme to its maximum. This also means that as the inhibitor concentration increases, the enzyme’s affinity of the substrate decreases. The Michaelis constant, Km, describes this. The Km is always the concentration of the substrate at half of the Vmax value. A high Km means that a large amount of substrate must be present to saturate the enzyme and cause it to operate at Vmax. Thus, the enzyme has a low affinity for the substrate when the Km is high. When the Km is low, a small amount of substrate is needed to saturate the enzyme, and the enzyme has a high affinity for the substrate. Thus, competitive inhibitors alter the Km, while the Vmax does not change. In general, when the concentration of an inhibitor is increased, the Km …show more content…
Mixed-mode inhibitors have the ability to bind to the free enzyme as well as the enzyme-substrate complex formed after the enzyme binds with the substrate. The inhibitor usually has a greater affinity for either the free enzyme or the enzyme-substrate complex. This inhibition type is called mixed-mode because it can be seen as a mixture of competitive inhibition, in which the inhibitor can only bind the enzyme if the substrate has not already bound, and uncompetitive inhibition, in which the inhibitor can only bind to the enzyme if the substrate has already bonded. Mixed-mode inhibitors alter both the Km and the Vmax of the