Tutorial Enzyme kinetics
1) The hydrolysis of sucrose (S) catalyzed by the enzyme invertase has been studied by measuring
the initial rate, rpo , at a series of initial concentrations of sucrose (CSO). At a particular temperature
and enzyme concentration, the following results were obtained (Chase et al., 1962):
cso/mol L-l 0.0292 0.0584 0.0876 0.117 0.146 0.175 0.234
rpo/mol L-1s-l 0.182 0.265 0.311 0.330 0.349 0.372 0.371
Determine the values of Vmax and the michaelis constant Km in the Michaelis-Meten rate law.
2. The kinetic model of lactose hydrolysis by Aspergillus niger lactase can be described as follows
(Scott et al., 1985):
�� + �� ↔ ���� → �� + �� + ��
E + S ↔ ES
where S, P, Q, and E are lactose, galactose, glucose, and free enzyme.
a. Derive the rate equation for the production of galactose by using Briggs-Haldane
approach. b. Does galactose inhibit the reaction competitively or noncompetitively?