Slides.pdf

Metabolism adapts to changing environments and exhibits changes in enzyme activity even in constant environments, with significant alterations during the cell cycle. Research by Van Doorn et al. (1988) showed changes in enzyme activities involved in carbohydrate metabolism during the cell cycle of S. cerevisiae. A working hypothesis is that switching between pathways may improve overall efficiency, and a modeling approach considers the synthesis and degradation of enzymes, gene expression, and reaction flux. The goal is to minimize the total time needed to produce a certain amount of output metabolites, and a non-linear mixed 0-1 optimization problem is formulated to solve this. The model can be applied to various scenarios, including optimal MinMode solutions, and toy examples demonstrate the improvement possible through switching. Biomass production in central carbon metabolism is also considered, and optimal MinMode solutions are presented for different cases.