[The organization of metabolism : subcellular localization of glycolytic enzymes]

The subject of cellular metabolic organization (with focus on carbohydrate metabolism) is reviewed. The existence of a "soluble" phase in the cell is considered unlikely. A note of caution regarding metabolic compartmentation as shown by isotope studies is presented. Emphasis is given to the description of experiments purporting to show the influence of protein crowding, interactions between glycolytic enzymes, and reversible association to structural proteins or to organelles. The transient nature of those associations is considered to be particularly relevant to the organization and regulation of glycolysis. The proposed role of isozymes as structural determinants of metabolic compartmentation is stressed. A few studies based on immunocytochemical observations of glycolytic enzymes are briefly described. A list of questions whose answers are badly needed is presented.