Four-step linear pathway with Michaelis-Menten kinetics. A) Schematic representation of a four-step linear pathway coupled with enzyme dynamics. It consists in four enzymatic reactions, where the substrate (S
1) is converted into the product (S
4). B) Metabolite dynamics, expression rates and enzyme activation profiles that minimize the time needed to reach a given steady state and the corresponding enzyme consumption, see Equation (16). C) Pareto front obtained by minimizing the time and the enzyme cost needed to reach a certain amount of product using Equation (23). D) Enzyme profiles for the points P
2 and P
3 of the Pareto front using ρ=120 steps with fixed duration. Enzyme and metabolite concentrations are expressed in concentration units (mM) and time in seconds (s).