I believe you could use FIRE.
we consider an organism had metabolizing capability if it manage to absorb nutrients from substance, and secrete it.
Fire has similar feature with this (for example, if it got near woods, fire will consume the woods and got bigger from it, and secrete ash after it done)
Trophic levels can be represented by numbers, starting at level 1
with plants. Further trophic levels are numbered subsequently according
to how far the organism is along the food chain.
Level 1: Plants and algae make their own food and are called primary producers.Level 2: Herbivores eat plants and are called primary consumers.Level 3: Carnivores that eat herbivores are called secondary consumers.Level 4: Carnivores that eat other carnivores are called tertiary consumers.Level 5: Apex predators that have no predators are at the top of the food chain.*Hope that helps XD*
Other biological molecules that contain the element of N would be nucleic acids such as DNA and or RNA. There are found in the nucleotides that constitute or make up these nucleic acids.
Skin muscle etc.yk look it up too :()
Autotrophs are organism that is a Heterotroph.
