Figure 1

A scheme illustrating the rules that control the dynamics of the enzymatic reaction steps i. Here S, P, E, SE and PE stand for substrate, product, enzyme, substrate/enzyme and product/enzyme, respectively. The probability of motion is 1/k, k = 1 to 4 being the number of unoccupied neighboring cells; probability equal to 1 is postulated for S(i) and E(i) to join, as well as for PE(i) to disjoin. The transitional probability for the PE(i) formation is assumed equal to 0.5, which makes the first reaction step reversible.