Analogue and digital representations of enzyme kinetics.

In the considerable time interval between the establishment of chemical equations for enzyme action by Michaelis and Menten (l), and their extension by Briggs and Haldane (Z), to the present time, there has been no satisfactory mathematical approach to a detailed comparison of the over-all or intermediate kinetics with those of the chemical equations. In spite of other efforts to make approximate solutions (3, 4) we showed some time ago that the mechanical differential analyzer (5) and more recently the electronic analogue computer (6) could be used in the solution of these problems. However, both the mechanical differential analyzer and the electronic analogue computer have definite limitations in terms of the number of components of an enzyme sequence that can be represented. In order that multienzyme systems might be adequately studied (7-ll), we began, in 1953, to develop a program for a digital computer that would allow the representation of 40 simultaneous chemical reactions. In the preceding paper (11) the method of use of the digital computer program and the types of representation have been described in detail. It is the purpose of this paper to establish criteria for the accuracy of the digital computer program for a simple enzyme system by comparing it with solutions previously obtained from the mechanical differential analyzer.