Question

An element that the main component of atmospheric air and plays an important role in any ecosystem: this is needed by all organisms to form proteins, ATP, and nucleic acids.

Answer 1

The answer is nitrogen. It comprises approximately 78% of the atmospheric air. Nitrogen can be found in most life processes including as a component of amino acids –amino group (NH3-). It is also involved in the structure of nucleosides that are critical in the formation of nucleotides and ATP.

Answer 2

The phrase "main component of atmospheric air" already points to nitrogen as it makes up 78% (mole basis) of atmospheric air. Nitrogen is the main element found in amino acids (amino group refers to NH3) and amino acids make up almost all important life molecules such as proteins, DNA, and ATP.