The effect of pH on the activity of an enzyme was examined. At its active site, the enzyme has an ionizable group that must be positively charged for substrate binding and catalysis to take place. The ionizable group has a pKa of 6.0. The substrate is negatively charged throughout the pH range of the experiment. At what pH = 9, the enzyme will be operating at answer is either Vmax, 1/2 Vmax or less than 1/2 Vmax (type in one of the 3 phrases as they are written here.)

An enzyme catalyzes the reaction M-N. The enzyme is present at a concentration of 0.0000000022 M, and the Vmax is 0.0000028 Ms1. The Km for substrate is 5.5 µM. Calculate kcat-

Concentrations in biochemical systems are often very dilute. Consequently, scientific notation and logarithms are often used to express concentrations. In scientific notation, numbers are expressed as coefficient x 10" To convert a number to scientific notation, proceed as follows: 1. Move the decimal place so that there is one digit in front of the decimal. 2. Account for the moved decimal in the value of x. If the decimal moved to the right, x is negative; if it moved to the left, x is positive. A logarithm is basically an exponent. Unless otherwise indicated, a logarithm is the a of 10". The numbers after the decimal point are significant; the number before the decimal just identify the location of the decimal point for the number. Notice that it is easy to estimate a logarithm from scientific notation; it's the exponent! Logarithms are commonly used to express the concentration of H. The pH is defined as pH= log (In), where the base number is 2.303. The same general rules as logs…

In a uni uni enzyme reaction, what is the substrate concentration relative to Km when anenzyme operates at 0.95 * V. What about 0.99 * V?