Final answer:
Cellular death typically occurs after about 10 minutes without oxygen, with brain cells being particularly susceptible due to their ATP demands. Immediate medical interventions like CPR can sometimes prevent permanent damage.
Step-by-step explanation:
Cellular death occurs after approximately 10 minutes without oxygen. Atmospheric air contains about 20 percent oxygen, which is essential for the production of ATP (adenosine triphosphate), the energy currency of the cell. Brain cells, in particular, are highly sensitive to oxygen deprivation because they require a continuous supply of ATP.
Without oxygen, brain damage is likely to occur within five minutes, and cellular death leading to the death of the individual is likely within ten minutes. However, under certain conditions, such as in cases where an individual is submerged in very cold water, the time before brain death can be extended. This is why immediate resuscitation efforts are important in near-drowning incidents, especially in cold water. In summary, while brain death and cellular death typically occur within a very short time frame without oxygen, prompt medical intervention like CPR can sometimes prevent permanent damage and save an individual's life.