What process animates cells and gives life to lifeless matter?

[Annihilus]

[Cybele]

Quite interesting and nicely explained. First time I've heard about the Krebs cycle.
I'll look more into this.

[Vessna]

Good refresher on molecular bio.
I have never thought of Krebs cycle as a way to differentiate living from non-living.
For no-bio people, Krebs cycle is a metabolic pathway that produces energy in cells by converting oxygen into ATP molecule. It occurs in mitochondria in humans.
Viruses are considered nonliving, despite being able to replicate itself. They use host cell for their metabolic needs. I've always found it fascinating.