Figure 2.

Examples of coarse-grained approach to physiology and cell cycle study. (a) Proteome partitioning: in this study of coordination between cell growth and protein composition, the proteome is divided into two ‘sectors’ depending on whether the protein is ribosomal (R) or non-ribosomal (non-R). In steady-state growth, the ratio between R and non-R sectors is determined by balance between the supply and demand of amino acids. If some ribosomes become inactive by sub-lethal concentration of antibiotics that inhibits translation, demand for amino acid reduces. This eventually also reduces supply of amino acids because less ribosomes are available to make the proteins for catabolism, causing reduced amino acid flux. (b) Coarse-grained view of intracellular processes underlying cellular reproduction presented in recent study [38•]. (c) A ‘metabolic sensor’ that coordinates metabolism and cell division. The common substrate UDP-glucose is converted from Glucose-6-P (shown as a hexagon) in the glycolysis pathway after two consecutive steps. These enzymes together with UDP-glucose serve as the metabolic sensor that passes the information about nutrient quality from the metabolism kernel to the cell division kernel.