Final answer:
Brain cells are at risk of damage within five minutes without oxygen, with brain death likely after about six minutes and probable death within ten minutes. Immediate emergency response like CPR is crucial in increasing chances of survival.
Step-by-step explanation:
How soon does the brain start to die without oxygen?
Without oxygen, the brain cells start to be at risk in as little as five minutes, and brain damage is quite likely to occur. Continuing the lack of oxygen, death is probable within ten minutes. It's essential to understand that the brain requires a constant supply of oxygen to produce ATP, a molecule vital for energy transfer within the cells. Brain death is likely after approximately six minutes without oxygen, although there are exceptions such as cases involving young individuals in cold water where survival up to an hour is possible due to reduced metabolism. Immediate responses like CPR can be life-saving, especially if commenced within minutes of oxygen deprivation.