What does it alive

We know the cycle of life: we are born, grow, become adults and do various things, including among our children, age, .. die.
Beyond chemical reactions, interactions of physical factors beyond everything that biology or genetics, man is much more. Analyzing every aspect of his life, and every part of his body: marvel. So well done! A perfect machine. Never man will not be able to reproduce it.
Yet what is life? What does it mean to live?