Physiological regulations and compartments in cells

Quantitative short-term regulation of a chemical component (glucose) in a single cell (hepatocyte of rat) is represented by an "equilibration diagram," which relates concentration of the regulated component or substrate (glucose) to loss and to gain of the same substrate (glucose). Loss and gain are separately active through specific enzymatic processes. Evidence indicates that some of these processes require the presence of subcellular compartments for their participation.