Interesting that you point to the prokaryotic cell. Simply stated, prokaryotes are molecules surrounded by a membrane and cell wall. An evolutionary example of early life.
You seem to be saying that death is important because it motivates us to stay alive. I'm not sure if the "survival instinct" is a result of the fear of death. If we look at the prokaryote cell, its doesn't have a central nervous system, it doesn't even have sexual reproductive capabilities. It certainly does not crave security and permanency yet it displays an "instinct for survival". This is evident in its ability to perform photosynthesis, as in... nourish itself in order to survive. In some cases prokaryotes are mobile... able to maintain survival by moving away from or toward stimulus it either wants or rejects by way of flagella that evolved into the cell wall of some of these cells. But I highly doubt the prokaryote is aware of "death" as a "threat" to its survival. It has somehow, naturally developed a propensity to survive.
It would be an interesting excercise to try and trace back to the origin of the "survival instinct". Is it a universal phenomenon? Does it apply to both living and non-living entities? Is what we see as the "survival instinct" a reflection of the tendancy for all phenomena to... "survive"?