Enzyme Lab

1104 Words5 Pages
Introduction: Enzymes are biological macromolecule that acts as catalyst and speed up reaction by lowering the activation energy of the chemical reaction without altering the thermodynamic of reaction (study.com). However, the enzymes are not consumed in the reaction and they will regenerate (study.com). According to rsc.org, enzymes possess an active site, and the chemical species that binds to an enzyme active site is called the substrate (rsc.org). Enzymes catalyze reactions by interacting with the substrate and the subsequent transition state. These interactions release energy and therefore stabilize the transition state, which ultimately lowers the activation energy of the reaction (rsc.org). The goal of this experiment is to measure…show more content…
These molecules are called enzyme inhibitors (chem.wisc.edu). In this experiment, we will look at three types of inhibition: competitive, non-competitive, and mixed mode. Competitive inhibitors are molecules that compete with the substrate for binding to the enzyme active site due to the similar structure to the substrate and prevent the substrate binding. It only binds to free enzyme. Increase substrate concentration can eliminate the effect of the competitive inhibitor. Competitive inhibitors change Km, but the Vmax remains unchanged (chemistry.elmhurst.edu). Non-competitive is a molecule that binds to a site different from the active site and prevents product formation. It only interacts with enzyme complex. This alters the 3-D conformation of the enzyme, so that the substrate still binds to the active site but no longer help stabilize the transition state or catalyze the reaction. We cannot use the increasing of substrate concentrations to overcome non-competitive like competitive. Non-competitive inhibitors decrease the Vmax and Km (chemistry.elmhurst.edu). Mixed mode inhibitors are inhibitors have affects of both competitive and non- competitive inhibition. They affect both the enzyme’s affinity for the substrate and the maximal rate of catalysis. Mixed mode inhibitors alter both Km and Vmax…show more content…
The reciprocal formula was typed “=1/” and the [S] cell was selected. The reciprocal of V0 was also done the same way. This procedure was reiterate for I=5,15,20 and inhibitor 2 and 3 to yield all the reciprocal data. The plot for Lineweaver-Burk was constructed by using the Marked Scatter graph. The trend line, title and the equation were added to the graph used the chart layout. The graph also was set backward 0.1 period to see where the line hits the X and Y-axis and is used to identify what inhibitor the graph presented. The last part of this lab was calculate the Vmax and Km. The 1/Vmax data were entered in the cell based on the equation y=mx+b, where b is the y-intercept and m is the slope, displayed on the graph for each I=0, 5, 15, 20. The 1/Vmax was b value. Vmax value was calculated by formula =1/(1/Vmax). The -1/Km was calculated by using the y=mx+b equation. The 0 was plugged in Y and then solved for X (-1/Km). Km was calculated by the formula =1/(-1/Km). This procedure was repeated for inhibitor 2 and 3. Results and

More about Enzyme Lab

Open Document