Biologically, does life and death matter?
We human are scare of death. Because of that, we tend to apply that idea into everything we can observe, even if it's meaningless. But why is death scary? Isn't it because when you die, you stop function anymore?


Fear of death is hard-wired into our nervous systems. A thirsty wildebeest will approach crocodile-infested water very, very reluctantly. The wildebeest isn't thinking about the selfish gene or the loss of his function in the world; he's hardwired to be afraid of the situation. The same is true for any prey animal: fawn, rabbit, gazelle, mouse. The difference (maybe; simplifying for convenience) is that we are rational, and like all of our primitive fears (e.g., of the dark, when there really were sharp-toothed predators with better night vision than ourselves), we try to rationalize them. We also rationalize our existence. 


  Is the functionality of something the only thing that life cares?


Nature is red in tooth and claw. If you want to anthropomorphize Nature, then sure, we matter (we're destroying the earth at unprecedented speeds). If you believe in a spirit, we matter. But if you believe in none of it, the only purpose we serve is to propagate ourselves, and when the last of our species is gone, Nature will not care a whit. Just as it doesn't care that dinosaurs, wooly mammoths, passenger pigeons, tasmanian tigers or baiji river dolphin are gone.

It can be argued that in the grand scheme of things (and here I'm speaking of the entire Universe), biological life doesn't matter at all.