Assumption: the transition state (S*)and the substrate (S)are in equilibrium. in which K*is the equilibrium constant for the formation of S*,and v is the rate of formation of product from S*. The rate of the reaction is proportional to the concentration of S* Rate [S*] because only S*can be converted into product.Assumption: the transition state (S* ) and the substrate (S) are in equilibrium. in which K* is the equilibrium constant for the formation of S*, and v is the rate of formation of product from S*. The rate of the reaction is proportional to the concentration of S* Rate ∝ [S*] because only S* can be converted into product