How many net ATP are produced per glucose molecule during glycolysis in humans?

• A. 2 net ATP (plus 2 NADH, which yield additional ATP via oxidative phosphorylation).
• B. 4 net ATP
• C. 2 net ATP only
• D. 6 net ATP

Answer: (A)

Glycolysis yields a net of two ATP per glucose. That’s because two ATP are spent early to prime the glucose, and later four ATP are produced during the payoff steps, giving a net gain of two. At the same time, glycolysis also generates two NADH molecules, one from each half of the glucose split. Those NADH molecules can drive more ATP production later through oxidative phosphorylation, depending on how they are shuttled into the mitochondria. So the best answer describes two net ATP plus two NADH that can yield additional ATP downstream. The other options miss the actual ATP accounting inside glycolysis or don’t acknowledge the NADH contribution.