Enzymes catalyze chemical reactions. What constitutes the active sire of an enzyme? What are the turnover number (k_cat), the Michaelis constant (K111), and the maximal velocity ( V_max,) of an enzyme? The k_cat for carbonic anhydrase is 5 X 10⁵molecules/s. This is a "rate constant" bur nor a "rate." What is the difference? By what concentration would you multiply this rate constant in order to determine an actual rate of product formation (V)? Under what circumstances would this rare become equal to the maximal velocity ( V_max) of the enzyme?