In glycolysis, 4 ATPs and 2NADH are produced but in the process 2 ATP are used up, therefore the only 2 ATP can be said to be profitably produced.
The two ATPs are used up in the first and third steps of glycolysis. There are 10 steps in total.
Glycolysis is the metabolic process that acts as the foundation in both anaerobic and aerobic cellular respiration. In glycolysis, glucose is converted to pyruvate and the process takes place in the cytoplasm of the cell.