Nitrogen is also a very important compound for an ecosystem. Despite its abundance in the atmosphere (79% of air is nitrogen), it is often in very limited supply. This is because it is required by plants as ammonium (NH4+ or nitrate (NO3-). After carbon, nitrogen is the most important atom in organic compounds. It is particularly important in DNA, and amino acids, which make up proteins.
The Carbon Cycle
All life is based on carbon; it is contained in proteins, carbohydrates; indeed all organic molecules contain carbon. So it is the most important nutrient in an ecosystem. The carbon cycle involves several stages of carbon being fixed (incorporated as part of) by plants from the atmosphere. This carbon is transferred to consumers by eating, or it becomes fossil fuel in fossilisation.
Because the vaccine is an antigen from living, weakened or killed microorganisms that activate the immune system and the body produces protective antibodies.
