Glycolysis is considered a universal pathway that oxidize one molecule of a glucose molecule to produce two molecules of pyruvate, with energy conserved as ATP and NADH.
All 10 glycolytic enzymes are released from the cytosol of eukaryotic cells, and all 10 intermediates products are phosphorylated compounds of three or six carbons.
There are two phases of the glycolysis process: preparatory phase and payoff phase.
In the preparatory phase of glycolysis, two molecules of ATP is invested to convert glucose to fructose 1,6-bisphosphate. The bond between C-3 and C-4 of the six-carbon glucose is then broken to yield two molecules of triose phosphate: dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.
The payoff phase starts with the oxidation of glyceraldehyde 3-phosphate.
Each of the two molecules of glyceraldehyde 3-phosphate derived from glucose are oxidized to produce two molecules of pyruvate.
In the reactions of this phase, the energy is conserved in the form of one NADH and two ATP per triose phosphate.
The net equation for the overall process is :
Glucose + 2NAD + 2ADP + 2Pi →2 pyruvate + 2NADH + 2H + 2ATP + 2H2O.