Glycolysis

Glucose G6P F6P F1,6BP GADP DHAP 1,3BPG 3PG 2PG PEP Pyruvate HK PGI PFK ALDO TPI GAPDH PGK PGM ENO PK Glycolysis The metabolic pathway of glycolysis converts glucose to pyruvate via a series of intermediate metabolites.    Each chemical modification is performed by a different enzyme.    Steps 1 and 3 consume ATP and    steps 7 and 10 produce ATP. Since steps 6–10 occur twice per glucose molecule, this leads to a net production of ATP.

Glycolysis is the metabolic pathway that converts glucose (C₆H₁₂O₆) into pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The free energy released in this process is used to form the high-energy molecules adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide (NADH).^[1] Glycolysis is a sequence of ten reactions catalyzed by enzymes.

The wide occurrence of glycolysis in other species indicates that it is an ancient metabolic pathway.^[2] Indeed, the reactions that make up glycolysis and its parallel pathway, the pentose phosphate pathway, can occur in the oxygen-free conditions of the Archean oceans, also in the absence of enzymes, catalyzed by metal ions, meaning this is a plausible prebiotic pathway for abiogenesis.^[3]

The most common type of glycolysis is the Embden–Meyerhof–Parnas (EMP) pathway, which was discovered by Gustav Embden, Otto Meyerhof, and Jakub Karol Parnas. Glycolysis also refers to other pathways, such as the Entner–Doudoroff pathway and various heterofermentative and homofermentative pathways. However, the discussion here will be limited to the Embden–Meyerhof–Parnas pathway.^[4]

The glycolysis pathway can be separated into two phases:^[5]

1. Investment phase – wherein ATP is consumed
2. Yield phase – wherein more ATP is produced than originally consumed