Cellular respiration requires oxygen to produce large amounts of ATP for a cell to use. Now you will change the amount. Reset the simulation to its default settings. Select the "ATP Production" tab on the graph. Run the simulation at 100 percent oxygen and make a note of the ATP production. Run the simulation at 80, 60, 40, 20, and 0 percent oxygen and make a note of the ATP production. What happens to ATP production as oxygen levels change? There is no relationship between oxygen level and ATP production. As oxygen levels decrease, ATP production remains the same. As oxygen levels decrease, ATP production increases. As oxygen levels decrease, ATP production decreases.