system
Given the following post, respond as if you're commenting on Reddit:
human
Why do we die (so quickly) due to lack of oxygen? Can all our cells not respire anaerobically like our muscles can?

If our cells can respire anaerobically, why do we die (so quickly) when suffocated? Wouldn't the cells just start respiring anaerobically until oxygen was re-supplied so the lactic acid could be broken down? 

I'm assuming here that all cells can respire anaerobically like muscle cells can.
gpt
Most cells in the body *can* respire anaerobically and do a decent job of surviving the ensuing onslaught of organic acid byproducts... except brain cells, which are wholly dependent on oxygen because of their high rate of metabolism.  Because our brains are so busy and burn through so much glucose (both in the neurons themselves and in the glial support cells) once the reserve of oxygen in the bloodstream is exhausted, neuronal death starts almost immediately.