Is this a 'ghost in the machine' sort of thing? BEWARE, FOR YOU HAVE UNLEASHED THE NERD!!!!
As far as I'm concerned, life can essentially be defined by these three simple things...
1. Things that are alive eat food, in that their continued survival requires the regular intake of some form of substance that makes for continued functionality.
2. Things that are alive have independent thought processes and/or emotional responses, and so can think and choose for themselves. At the bare minimum, they respond to external stimuli instead of just sitting there.
3. Things that are alive can reproduce, in that they make more of themselves.
Let's address each point one by one.
1. Transformers need energon, and can't go without for long. Wouldn't that make it like their equivalent to food? Otherwise, why were the Decepticons in such a big yank about getting it in G1?
2. Doesn't the fact that they rebelled against their creators in G1 imply that they were capable of independent thought? It's impossible to want to think for yourself if you're not capable of it. Isn't the very act of desiring this an example of independent thought? And it goes without saying that they at least know what's going on around them. DUH!!!
3. If you're a machine and you're making more machines that are one heck of a lot like you, that counts as reproduction. What, after all, is reproduction but making more of whatever you are?
In short, organic materials and processes may be the scientific definition of life, but that's NOT the only way to define it.
...And if you've read this whole thing without falling asleep, congratulations.