Question

Can any organism use nitrogen directly from the atmosphere ??

Answer 1

No before it Nitrogen Fixation is Necessary in Nitrates and Nitrites.Any of the organism cannot use it directly.

Hope it helps ✌✌

Answer 2

most organisms including humans can't use nitrogen directly from the atmosphere


oxygen can react with carbohydrates by an exothermic reaction, thus delivering energy.  I do not know of similar reaction of nitrogen with possible food components.
nitrogen is rather useful in combined state as nitrites nitrates ammonia proteins etc