what is the fate of pyruvate produced during glycolysis
The fate of pyruvate depends on whether the oxygen is available or not. Under anaerobic conditions it is converted to lactate. In muscle cells glucose is converted to pyruvate. In the absence of oxygen pyruvate converts to lactate by the enzyme lactate dehydrogenase. This reaction leads to production of NAD+ which replenishes the NAD+ used in the glyceraldehydes-3-phosphate dehydrogenase reaction and carry on glycolysis.
Yeast do not synthesize lactate, however, they undergo anaerobic respiration synthesizing ethanol. Pyruvate is converted to ethanol in anaerobic respiration in yeast. Here pyruvate is decarboxylated to ethanol.
In the presence of oxygen it is converted to carbon dioxide, water and energy.