The second half of glycolysis is known as the 'pay-off phase', by the net gain of the energy-rich molecules ATP and NADH. Since glucose leads to two triose () sugars in the preparatory phase, each reaction in the pay-off phase occurs twice per glucose molecule. This yields 2 NADH molecules and 4 ATP molecules, leading to a net gain of 2 NADH molecules and 2 ATP molecules from the glycolytic pathway per glucose molecule.