What is the fate of pyruvic acid in an organism?

The fate of pyruvic acid in an organism depends on the metabolic conditions. In the presence of oxygen, pyruvate is converted into acetyl-CoA, which enters the citric acid cycle for aerobic respiration. In the absence of oxygen, pyruvate undergoes fermentation, either becoming lactate in muscle cells (lactic acid fermentation) or ethanol and CO2 in yeast and some microorganisms (alcoholic fermentation). The organism’s metabolic state determines which pathway is activated.