Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 3

Rate Enhancement by Catalysts. The decomposition of H 2 O 2 to H 2 O and O 2 shown in Reaction 6-2 can be catalyzed either by an inorganic catalyst (ferric ions)or by the enzyme catalase. Compared with the uncatalyzed rate, this reaction proceeds about 30,000 times faster in the presence of ferric ions but about 100,000,000 times faster in the presence of catalase, an iron-containing enzyme. Assume that 1 µ gof catalase can decompose a given quantity of H 2 O 2 in 1 minute at 25°C and that all reactions are carried out under sterile conditions.
(a)How long would it take for the same quantity of H 2 O 2 to be decomposed in the presence of an amount of ferric ions equivalent to the iron content of 1 µ g of catalase
(b)How long would it take for the same quantity of H 2 O 2 to decompose in the absence of a catalyst
(c)Explain how these calculations illustrate the indispensability of catalysts and the superiority of enzymes over inorganic catalysts.