Figure 1.

Modular model example. (a)—inner structure of modules (SBGN). M1-M3 designate corresponding modules; two green rectangles A and B in M1 correspond to molecules A and B which form the complex A:B, while grey and red pentagons in M1 designate contact port for A and output port for A:B, respectively; two green rectangles C and C_p in M2 correspond to protein C and phosphorylated form of the protein, while green and red pentagons in M2 designate input port for A:B and output port for C_p, respectively; two green rectangles A and A_1 in M3 correspond to molecules A and A_1, while green and grey pentagons in M3 designate input port for C_p and contact port for A, respectively; two purple circles X and Z in M3 mean the additional substrate and product of the bimolecular reaction, correspondingly that is catalyzed by phosphorylated form of the protein C (green rectangle), (b,c)—modular diagram in two equivalent variants: without or with buses (white circles). Buses serve for cosmetic purposes only.