What are the two fates of pyruvate?

The two main fates of pyruvate are: 1) Conversion to Acetyl-CoA: In the presence of oxygen, pyruvate is converted into acetyl-CoA, which enters the citric acid cycle and produces ATP. 2) Fermentation: In the absence of oxygen, pyruvate undergoes fermentation. In muscle cells, it is converted into lactate, while in yeast, it is converted into ethanol and CO2. Both processes regenerate NAD+, enabling glycolysis to continue producing ATP under anaerobic conditions.