I understand why carbon is essential for life. It's able to form long chains and has four binding sites. But what about nitrogen? Proteins are the most important class of molecules for life (except maybe DNA), and they require nitrogen. Why can't we make enzymes and other structures without nitrogen? What's so special about nitrogen?

  • 4
    $\begingroup$ …or oxygen or hydrogen or carbon or sulphur or … You could ask this question on SE Chemistry, but I think they would expect you to study some chemistry first. $\endgroup$
    – David
    Oct 3 at 18:59
  • 2
    $\begingroup$ I think you need to distinguish between "why do OUR major functional macromolecules (proteins) require nitrogen?" and "would any similar life require nitrogen, or could alternative macromolecular chemistries be possible?". $\endgroup$
    – Armand
    Oct 3 at 19:43

Browse other questions tagged or ask your own question.