In which organ is lactic acid converted back to pyruvic acid?

Lactic acid is converted back to pyruvic acid primarily in the liver through a process known as gluconeogenesis. This conversion takes place when the body is in a state where it needs to recycle lactic acid, often following intense exercise or anaerobic respiration, which produces lactic acid as a byproduct. The liver plays a crucial role in maintaining glucose levels in the blood, and converting lactic acid back to pyruvic acid allows for the potential regeneration of glucose through further metabolic processes.

While other organs, such as the heart, can utilize lactic acid as a fuel source and may partially process it, the liver is specifically designed to conduct the conversion back to pyruvic acid effectively, facilitating its entry into the Krebs cycle or enabling its conversion back to glucose. This metabolic pathway is instrumental in the body’s effort to manage and utilize energy sources efficiently, particularly in conditions where oxygen is limited, and the need for quick energy reserves is elevated.