The catalytic response of an immobilized redox enzyme connected to the electrode by a freely diffusing mediator (cosubstrate) may depend of the Michaelis-Menten characteristics of the enzyme-redox cosubstrate system. How the electrochemical responses are related then to the corresponding rate constants, to the amount of enzyme on the electrode, to the concentration and to the mass transport parameters is analyzed in the framework of cyclic voltammetry, for the purpose of establishing diagnostic criteria and procedures for rate constant determination based on the shape, height and potential location of the catalytic responses. Two main kinetic regimes are discussed. The first one concerns systems in which the two enzyme forms are under steady-state conditions. The maximal effect of Michaelis-Menten kinetics is expected when the decomposition of the enzyme-cosubstrate complex is the rate-determining step. This case is analyzed in detail after removal of the steady-state condition. Although the derivation of diagnostic criteria and closed form expressions of the cyclic voltammetric responses is privileged, numerical simulation procedures are described that are applicable to the systems under discussion, but also, with little adaptation, to any other immobilized redox enzyme systems. (C) 2003 Elsevier Science B.V. All rights reserved.