What is anaerobic glycolysis?

Anaerobic glycolysis occurs when oxygen is limited or absent. In this process, glucose is metabolized to pyruvate, but instead of entering the citric acid cycle, pyruvate is converted to lactate (in animals) or ethanol and CO2 (in yeast) through fermentation. Anaerobic glycolysis regenerates NAD+ from NADH, allowing glycolysis to continue, though it produces much less ATP compared to aerobic glycolysis.