"**Nitrogen is needed in such great quantities because it is in every living cell**: it is in chlorophyll, whose excitation powers photosynthesis; in the nucleic acids DNA and RNA, which store and process all genetic information; and in amino acids, which make up all the proteins required for the growth and maintenance of our tissues. "The element is abundant—**it makes up nearly 80 percent of the atmosphere**, organisms live submerged in it—and yet it is a key limiting factor in crop productivity as well as in human growth. This is one of the great paradoxical realities of the biosphere and its explanation is simple: **nitrogen exists in the atmosphere as a non-reactive molecule** (N2), **and only a few natural processes can split the bond between the two nitrogen atoms and make the element available to form reactive compounds**." ([Location 1125](https://readwise.io/to_kindle?action=open&asin=B08SGC3TD3&location=1125)) --- **Tags** -- [[quotes]], [[nitrogen]], [[photosynthesis]], [[fertilisers]] **Source** -- [[202412030828 - B - How the World Really Works]]