Why is nitrogen needed by plants and animals?
to make proteins and amino acids
Nitrogen is an essential nutrient for plants. it is needed for the production of amino acids which make up proteins. it is also needed for the production of enzymes as they are made of proteins. Nitrogen is also the main component of chlorophyll. Without nitrogen, plants are unable to grow and Photosynthesize. Nitrogen is used by the plants and animals to produce DNA, proteins and the amino acids.
It doesn't. Nitrogen in its natural gaseous state is triple bonded and not broken down by plants or animals. Nitrogen must be fixed by bacteria the live symbioticly with plants so that the plants can use the nitrogen. ( the bacteria get sugar in this process ) Animals then get their nitrogen from consuming plants and other animals.