Why Do Plants & Animals Need Nitrogen?

Nitrogen is essential for plant and animal growth and function
••• Sujinphoto_iS/iStock/Getty Images

Nitrogen is a building-block element both in the atmosphere, where it is the most abundant gas, and in organisms. Its flow through earth’s atmospheric, geological and biological systems—the nitrogen cycle—is one of ecology’s grand choreographies.

Nitrogen's Biological Role

Nitrogen is required by plants and animals for production of proteins and amino acids.
••• Digital Vision./Digital Vision/Getty Images

Nitrogen, fundamental for cellular structure, is required by plants and animals for production of proteins and amino acids.

Photosynthesis

One of the components of chlorophyll is nitrogen.
••• TongRo Images/TongRo Images/Getty Images

One of the components of chlorophyll, the plant pigment that facilitates photosynthesis, is nitrogen. It plays a role in this immensely important transformation of solar energy.

Availability

Usable nitrogen is a limited commodity.
••• Margaryta Vakhterova/iStock/Getty Images

Although 78 percent of our atmosphere is comprised of nitrogen gas, usable nitrogen is a limited commodity. Most organisms can tap the element for growth and function only when, through a process called nitrogen fixation, it has been converted into ammonia or nitrates.

Nitrogen Fixation

Fixation is accomplished by bacteria in soil.
••• Geo-grafika/iStock/Getty Images

Fixation accomplished by bacteria in soil—often in symbiotic relationship with fungi and plants—provides the bulk of nitrogen available to the biotic community.

Nitrogen Cycle

Lightning passes nitrogen gas through the atmosphere.
••• Ivan Archipov/iStock/Getty Images

This gas passes through the atmosphere, rocks, lightning, plants and animals, facilitating growth and being liberated by organic waste and decay in a fundamental biogeochemical cycle.

Related Articles

Extract Your Own DNA and More With These Awesome Science...
Nitrogen Gas Vs. Carbon Dioxide
What Effect Does a Limiting Nutrient Have on an Ecosystem?
What Elements Make Up the Air We Breathe?
Roles of Cyanobacteria in the Ecosystem
How Does Photosynthesis Affect the Atmosphere of the...
What Is the Density of Nitrogen Gas?
What Are the Two Major Components of the Earth's Atmosphere?
What Are the Three Most Abundant Gases in the Earth's...
Percentage of Nitrogen in the Air
What Is an Ecosystem Made Up Of?
What Type of Vegetation Is Found in Coral Reefs?
What Are the Functions of Photosynthesis?
Main Types of Ecosystems
Things That Makes Up an Ecosystem
How Does Eutrophication Affect pH?
How Does an Ecosystem Survive?
What Role Do Decomposers Play in a Food Chain?
Organelles Involved in Photosynthesis
The Cycle of Oxygen Through an Ecosystem
What is a Biogeochemical Cycle?