What must happen to a chain of amino acids before it becomes a functional protein?

They must go through termination

Explanation:

During termination, the ribosome unbinds from the mRNA, and the amino acid chain goes on to be processed and folded to make the final, functional protein.

significant amounts of nitrogen oxides, carbon monoxide, and other pollution

explanation:

passenger vehicles are a major pollution contributor, producing significant amounts of nitrogen oxides, carbon monoxide, and other pollution. in 2013, transportation contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air.

not sure if this is what you'r looking for eubacteria and archaebacteria