The complexity of prokaryotic and, exceedingly, of eukaryotic cells, challenges the implementation of methodologies to determine causality and quantify intracellular dynamics. Though stochastic thermodynamics can effectively quantify the dynamics of single proteins or complexes, there is no statistical approach that can generalize subcellular microstates to derive the macrostates of a whole cell. Onsager reciprocity, a coupling between thermodynamic flows, has not been used systematically to quantify and establish causality among cellular dynamics. A prototypical thermodynamic profile of the cell is formulated as a model system to enable representation of its dynamics as force-driven thermodynamic flows. The explanative potential of the methodology of thermodynamic reciprocity is validated against molecular mechanisms wherein the coupling between internal fluxes is recognized. Its predictive potential is then tested on mechanisms wherein coupling is unacknowledged, ruling out reciprocity between the contractile ring of the bacterial ortholog of tubulin, which facilitates the separation of dividing Escherichia coli cells, and the bacterial actin ortholog, which polymerizes along the cells' walls. In contrast, reciprocity is identified between the actomyosin ring that facilitates the division of fission yeast cells and treadmilling longitudinal micro-tubules. Directly pertinent to the definition of the cell's prototypical thermodynamic profile, the reciprocity that had been suggested between AMP-regulated kinase (AMPK) and mechanistic target of rapamycin (mTORC1) in the regulation of cell proliferation is confirmed thermodynamically.