Gluconeogenesis is the production of glucose from non-carbohydrate sources through a complex series of metabolic pathways. It occurs primarily in the liver and kidney cytosol and produces approximately 1 kg of glucose per day, which is essential for brain function and as an energy source for muscles. The major precursors for gluconeogenesis are lactate, pyruvate, amino acids, glycerol, and propionate derived from the breakdown of proteins, fats, and certain metabolites. The pathways involved closely mirror glycolysis except for a few irreversible steps that are bypassed by alternative enzyme-catalyzed reactions in order to synthesize glucose from these precursors.