The metabolic pathways of exogenous pyruvate and their relationships to the consumption of [H+]
First, pyruvate is oxidized into CO2 and H2O, which consumes an equal-molar [H+]. Second, when pyruvate is reduced to lactate, the process consumes an equal-molar [H+]. Finally, the transformation of pyruvate into glucose by gluconeogenesis consumes double-molar [H+].
[H+]: The cytosolic proton enters the mitochondria; [H+] (red): The proton being consumed in different glucose metabolic pathways; MCT. Monocarboxylate transporters; PDC. Pyruvate dehydrogenase complex; acetyl-CoA. Acetyl coenzyme A; PC. Pyruvate carboxylase; NAD+. Oxidized nicotinamide adenine dinucleotide; NADH. Reduced nicotinamide adenine dinucleotide; LDH. Lactic dehydrogenase; TCA. Tricarboxylic-acid.