system
Given the following post, respond as if you're commenting on Reddit:
human
After death how long do processes like digestion or cell regeneration continue to go on and what ultimately stops them?

I would imagine that the processes don't stop immediately.
gpt
In short, what ultimately stops cell processes after death is lack of oxygen. Without oxygen ions to fix electrons on the cellular level, cells are unable to function or reproduce, and they begin to decay. 

For some cells that require constant oxygen (such as neurons) this can happen almost immediately (within minutes) after death. For other cells that are not quite as oxygen thirsty (such as in the transplant organs) this can take between 30 or 60 minutes. Structural cells which require even less oxygen, such as in bone and connective tissue, can survive for around 24 hours after death before cell death occurs.