Final answer:
Under anaerobic conditions, pyruvate is converted into lactic acid in the cytoplasm of the cell through a process called fermentation, facilitating continued ATP production in the absence of oxygen.
Step-by-step explanation:
Under anaerobic conditions, pyruvate is converted to lactic acid in a process known as fermentation. This occurs in the cytoplasm of the cell. Fermentation allows cells to continue generating a small amount of ATP through glycolysis when oxygen is scarce. Lactic acid acts as the final electron acceptor and helps regenerate NAD+, which is necessary for glycolysis to persist.
While this method of ATP production is effective for short bursts of energy demands, such as during intense exercise, it is not sustainable for long periods of time. The lactic acid created in this process can be transported to the liver to be converted back into pyruvate and eventually glucose, as part of the Cori cycle.