How many ATP molecules does the phosphagen system produce?

The phosphagen system primarily relies on creatine phosphate to quickly regenerate ATP during short bursts of high-intensity exercise. This system is crucial for activities that require immediate energy, such as sprinting or heavy lifting, and functions primarily in the first 10 seconds of intense activity.

In this system, one molecule of creatine phosphate can immediately donate a phosphate group to ADP to form ATP. Therefore, the response is accurate in stating that the phosphagen system produces one ATP molecule per molecule of creatine phosphate used. This rapid energy production is essential for high-intensity performance, as it allows an athlete to sustain peak effort without the lag time associated with other energy systems like glycolysis or aerobic metabolism.

Other options represent quantities of ATP associated with different metabolic pathways rather than the phosphagen system specifically.