When is Anaerobic processes NADH transfer electrons to the pyruvate produced during?

Anaerobic processes, such as fermentation, involve the conversion of glucose to pyruvate through glycolysis, which generates NADH. In the absence of oxygen, NADH transfers its electrons to pyruvate, resulting in the formation of products like lactic acid or ethanol, depending on the organism. This transfer is crucial for regenerating NAD+, allowing glycolysis to continue and produce ATP in anaerobic conditions.