Glycolysis
Japanese: 解糖系（グリコリシス）
The fundamental metabolic pathway that breaks glucose into pyruvate. Operating both aerobically and anaerobically, it is the starting point of all fermentation.
Glycolysis is the metabolic pathway that breaks one glucose molecule into two pyruvate molecules, yielding 2 ATP. Comprising 10 enzymatic steps, it operates regardless of oxygen availability.
All fermentation pathways begin here. When pyruvate becomes ethanol, it's alcoholic fermentation; when it becomes lactic acid, lactic acid fermentation; when it enters the TCA cycle, aerobic respiration—glycolysis sits at the metabolic 'crossroads.'
Elucidated in the 1940s by Gustav Embden and Otto Meyerhof, this pathway is shared by virtually all life on Earth. Yeast, lactic acid bacteria, and humans all use the same glycolysis to extract energy from glucose—a fact that speaks to life's universality.