The two stages of glycolysis are:
  1. NADH Production: Four high-energy electrons are passed to the carrier NAD+ to produce NADH. NADH carries these electrons to the electron transport chain.
  2. ATP Production: Two ATP molecules are “invested” to get the process of glycolysis going. Overall, 4 ATP molecules are produced, for a net gain of 2 ATP per molecule of glucose.
The following are marked on the diagram: Glucose Cytoplasm NAD+ NADH ATP ADP Pyruvic Acid To Krebs Cycle To Electron Transport Chain