On Earth life has six fundamental building blocks for life with them being Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorus, and Sulfur. (1) Those elements of help make up more complex life through amino acids, proteins, nucleic acids / DNA, along with a lot of other things. (2) (3)
Though when it comes to the possibility of extraterrestrial life and xenobiology some individuals like to explore the idea that not all life has to use the exact same forms of life found on Earth. Most popular of which seems to be finding alternatives for Carbon and solvents. (4) (5) (6)
Now when I looked through this all it seemed like the possible forms of alternate life had little bounds for having something in common. Carbon based could be replaced with Silicon or Boron-Nitrogen, Phosphorus replaced by Arsenic, water replaced with ammonia, and so on with varying degrees of possibility. The only thing that cannot be replaced it seems is the need for Nitrogen.
At first I foolishly thought that like Carbon being replaced with Silicon or Phosphorus being replaced with Arsenic one could just use the same idea with Nitrogen. The problem is below Nitrogen is Phosphorus, already being used for the building blocks of life. I tried to think of a way that Phosphorus could just replace Nitrogen completely somehow and do the almost same job, though learning from the objections to Silicon based life just because elements share the same family does not mean they can replace each other.
So that left me rather stuck, as we understand how life works right now, is all life in the universe bound to have to use Nitrogen in some way or another? Or have I completely messed up, missed something, and dealing with a case of Nitrogen chauvinism?