Conversion of a six-carbon carbohydrate to two pyruvic acid molecules with accompanying reactions that release atp and hydrogen atoms is called

Glycolysis

Glycolysis is the metabolic pathway that converts glucose C₆H₁₂O₆, into pyruvate, CH₃COCOO - + H⁺. The free energy released in this process is used to form the high-energy molecules ATP and NADH. Glycolysis is a sequence of ten enzyme-catalyzed reactions.