In this article, you will become more familiar with how to draw titration curves of amino acids. A titration curve of an amino acid tracks how the pH changes and how the amino acid looks at different pH values as a strong base (OH equivalents) is added. Two important points to recognize on a titration […]
The isoelectric point is the point at which the net charge of the amino acid or protein is zero. You have learned how to determine the pI of amino acids. Finding the pI of peptides follow a similar process. Step 1: Write out the pKa values of the amino acid from low to high Step […]
Do you want to learn how to calculate the PI of amino acids with and without ionizable side chains? Read on. The isoelectric point of an amino acid or protein is the pH at which the net charge is zero. Determining pI When There Is No Ionizable Side Chain If the amino acid does not […]
The amino group, carboxylic acid group, and side chain of an amino acid can be protonated (accept hydrogen) or deprotonated (release hydrogen) depending on the pH of the solution that the amino acid is in. Use the following relationship between pH and pKa to help you predict whether protonation or deprotonation will take place. Another […]
The relationship between velocity and the substrate concentration is illustrated by an asymptotic curve. The equation representing this curve is called the Michaelis-Menten equation. Where V0 = initial velocity, and [S] = concentration of substrate. In the asymptotic curve, the line approaches but never reaches Vmax. Therefore, it is difficult to calculate. Hence, for more […]
Michaelis-Menten plots can be used to identify the type of enzyme inhibition that is present. As you should remember, there are three main types of enzyme inhibition i.e., competitive, uncompetitive and noncompetitive. Competitive Inhibition In competitive inhibition, the inhibitor can be overcome by increasing the substrate concentration. Hence maximum velocity is reached. However, notice that […]
Enzyme kinetics refers to the rate of reaction that occurs as the environment of the enzyme changes. This concept is studied using a Michaelis-Menten plot, a plot showing velocity on the y-axis versus substrate concentration on the x-axis. The graph grows exponentially till it reaches a maximum point. The Vmax on the graph is the […]
Many biological reactions are catalyzed by enzymes. As you should remember, enzymes are proteins that speed up the rate of biochemical reactions. However, some reactions may not be needed at a certain time. Hence it may be necessary to slow them down or prevent them all together. This is achieved using molecules called inhibitors. There […]
While enzymes are essential to metabolic function they are not all needed at the same time, in the same amounts nor in the same cell. Therefore biological systems must regulate them so that they are available when and where they are needed. Several mechanisms are responsible for enzymatic activity. Feedback Inhibition Enzymes may be controlled […]
