Say a totally mechanical human/animal cell was created. If it had mechanical versions of mitochondrion and lysosome and so on, and functioned as a normal cell, would it be considered to be alive?
Could it be concidered true life, or just artificial?
Assuming it could reproduce and had some sort of metabolism, I would say yes.
Do you think the fact that it would be mechanical and not organic would keep it from being realized as being truely alive?
Mechanical in what way? You mean, perhaps, that it were built of silicon and various metals, but contained structural or functional analogues to all of the organelles in a human cell? It’s important to note that this would not be a human or an animal cell at all. You might call it a model.
Many definitions we have for “life” are rather ambiguous, precisely because the people who really should be able to tell you what life is do not always agree. In addition, other things apply to most or all life that we have found, though there is no indication that this would have to be true for all life. For example, all life we’ve found undergoes Darwinian evolution, requires liquid water, and utilizes carbon containing compounds (called organic compounds for this reason), etc. Various definitions of “life” commonly include, but are not limited to;
[ul]
[li]Reproduction[/li][li]Respiration[/li][li]Utilization of energy to maintain structure or function[/li][/ul]
If your mechanical cell can do each of these things, than we would have the difficult choice of either redefining in some technical sense what we mean by life, or adding a stepchild to the family tree. It is far more likely that more stipulations would be added to the definiton, IMO.
“Alive” != “organic”
I think it would fit some of the basic criteria for life. Some folks include, in the definition, the ability not only to reproduce, but the capacity to evolve. Can this synthetic cell do those two additional things? If so, I’d say it meets all of the criteria floated thus far for defining life. If it can reproduce, but has very limited or no capacity to evolve, perhaps some would describe it as alive. If not either, it’s a toy, a very convincing model of life.
Cider? Well, I guess you wouldn’t officially consider it alive until it was hard cider 
To go to the opposite extreme, a race of sentient robots, capable of reproducing themselves by smelting, milling, and manufacturing copies, would definately be considered alive, despite mechanically being nothing more than rods and pistons. Yes? And you can certainly imagine Autobots here, because I am.
Yes, I know, and that’s not my point. My point is, life is usually thought of as being organic. Anything else is just thought of as a machine. A computer with artificial inteligence or a robot or android, all are just machines. But, if you made a duplicate of a living cell, that was made of inorganic material, could you concider it truely alive?
Quantum Evolution:
Although there often a sharp line between Life and Death, the line between non-life and Life is a Wave.
Peace
r~
Dumb question, maybe (I wander into philosophy of science threads only infrequently)-- is there a set of criteria generally considered to define ‘live things’? I can think of a few possibilities (reacts to stimuli, reproduces, for example) but I can’t think of any that would cover everything we consider ‘alive’ but that wouldn’t apply to, say, fire. I mean, fire, viruses, and yeast: what do these not have in common, for example? Does it need proteins? If we ran into something analogous to life elsewhere, would we recognize it as having anything in common with our criteria set? Is there any kind of scientific concensus?
There are arguments about what exactly qualifies as life, but the last time I took a biology course (high school) I learned this list:
[ol]
[li]Growth[/li][li]Metabolism, consuming, transforming and storing energy/mass; growing by absorbing and reorganizing mass; excreting waste[/li][li]Motion, either moving itself, or having internal motion[/li][li]Reproduction, the ability to create entities that are similar to itself[/li][li]Response to stimuli - the ability to measure properties of its surrounding environment, and act upon certain conditions.[/ol][/li]
What exactly does that mean?
If it had all of the things mentioned earlier (growth, reproduction, metabolism, reaction, etc.) then I see no reason it wouldn’t be considered alive. If it lacked one of those then you would have a debate as to wether it is alive or not. I think if it lacked growth or metabolism it could be thought of as alive, but not reproduction or reaction. And if it can’t move, I don’t see any way for it to reproduce, react, metabolize or grow.