system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter / General science fiction and fantasy] How does the Avada Kedavera work? Does it work on types of inorganic life?

Does it stop the heart?  Cease brain functionality?  Flip all of the target's cellular "alive/dead" switches at once?  Perverse quantum immortality into a sort of quantum suicide?  Depending on how it happens effects the second question: who can it kill?

Could you stop the Terminator with it? (It's a universal kill switch)

What about an AI like Deep Think (Hitchhiker's Guide)? (I causes brain death)

How about an AI that has a noted "heart/soul" like Optimus Prime? (It stops the hear or rips out the soul)

Could a person with a pacemaker live through the curse?  (It ceases a specific function, which can be overcome by modern technology)

Are cyborgs like Darth Vader or General Grievous organic enough to be effected?  (It ceases a specific function, which can be overcome by future technology)

Are hiveminds like the Borg or the Geth immune?  (Brain death situation)

How about golems? (Magic based inorganic life)

Trolls with silicon brains?  (Magic based semi-organic life)

Thomas the Tank Engine? (Faith based inorganic life)
gpt
When Dumbledore and Lord Voldemort duelled in the Ministry of Magic, Dumbledore animated the centaur in the Fountain of Magical Brethren to use as a shield, which exploded when struck by a Killing Curse. That said, a decent *reducto* would have had a similar effect, it's possible that the statue broke because it was physically ripped apart instead. 

Additionally, the effectiveness of all magic spells is based on a question of mass and to a lesser extent distance. For the same reason you can't *accio* the moon and kill us all, an average lone wizard would not necessarily kill something big like a dragon, mountain troll or giant with a killing curse. This, coupled with their relative intelligence, is why giants make for effective troops in wizarding wars.