system
Given the following post, respond as if you're commenting on Reddit:
human
If I inhaled pure oxygen, could I hold my breath longer?

Knowing that the air we breathe is roughly 21% oxygen, could I hold my breath longer if I emptied my lungs and inhaled pure oxygen?  Simple logic says that I should be able to hold my breath 4 - 5 times longer, but I will guess that this logic is false.
gpt
The breathing reflex is not mediated by the amount of oxygen in the air, but the level of carbon dioxide. So regardless of what composition of oxygen you breathe in, the rate at which carbon dioxide builds up when holding your breath will remain the same, so the urge to breathe will still increase at the same rate.